Erythropoietin receptor antibodies

ABSTRACT

Monoclonal antibodies to the erythropoietin receptor are disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a national stage filing under 35 U.S.C. §371 of PCT/US96/09613 filed Jun. 7, 1996, which is a continuation-in-part of application Ser. No. 08/474,673 filed Jun. 7, 1995, now abandoned.

FIELD OF THE INVENTION

The present invention relates generally to the generation of monoclonal antibodies by use of a selected antigen: and more particularly to the generation of monoclonal antibodies which are receptor agonists.

BACKGROUND OF THE INVENTION

A vast majority of receptors of the single transmembrane class respond to ligand binding by some form of aggregation. This aggregation can be between identical receptor subunits (as in homodimerization, homotrimerization, etc.) or between different receptor subunits (as is heterodimerization, heterotrimerization, etc). This aggregation appears to be part of the signal for the target cell to respond biologically, in that mutants of the ligand which are unable to interact with the second subunit are still able to bind, but no longer cause dimerization and biological activation of the receptor [P. R. Young, Curr. Opin. Biotech., 3:408-421 (1992)].

For example, there is evidence in the literature that suggests dimerization of the erythropoietin receptor (EpoR) upon ligand binding [S. S. Watowich et al., Molec. Cell Biol., 14:3535-3549 (1992) and S. S. Watowich et al., Proc. Natl. Acad. Sci., USA, 89:2140-2144 (1992)]. Reports about IL-6 have indicated that its second subunit gp130 may dimerize upon IL-6 binding [M. Murkami et al., Science, 260:1808-1810 (1993)]. for some receptors in which homodimerization is induced by ligand binding, monoclonal antibodies (mAbs) were discovered which had agonist properties. These include mAbs to EGF, TNF and growth hormone receptors [A. B. Schrieber et al., J. Biol. Chem., 258:846-853 (1983); L. H. K. Defize et al., EMBO J., 5:1187-1192 (1986); H. Engelmann et al., J. Biol. Chem., 265:14497-14505 (1990); and G. Fuh et al., Science, 256:1677-1680 (1992)]. In each case, these mAbs, by virtue of their two antigen recognition sites, were able to bring together two receptors and thus activate them. Fab fragments made from these mAbs were inactive. In some cases, the apparent affinity of the antibody for receptor was comparable to that of the ligand, e.g., growth hormone [Fuh et al., cited above].

It has also been discovered that antibodies to IL-3 receptor have agonist properties [Suguwara et al., J. Immunol., 140:526-530 (1988)]. Previous literature has described the production of anti-erythropoietin receptor antibodies [A. D'Andrea et al., Blood, 82:46-52 (1993); A. D'Andrea et al., Blood, 84:1982-1991 (1994) and M-G Yet et al., Blood, 82: 1713-1719 (1993). See also, PCT Application WO96/03438 published Feb. 8, 1996. While the Yet et al., reference suggests the occurrence of possible EPO-like activity in one mAb, the mAb is not characterized. Neither Yet et al., nor the other literature provides any reproducible manner of generating agonist mAbs.

There remains a need in the art for the development of additional mAbs which have an affinity for receptors comparable to that of the ligand, and which can act as agonists of the receptor.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a method for reliably generating an antibody which is an agonist of a receptor. This method employs as the immunizing antigen, a recombinant immunogen which consists of a first extracellular domain of a receptor molecule spaced apart from a second extracellular domain from that receptor by a bridging moiety. The bridging moiety places the first domain and the second domain into a functional proximity which mimics the functional domain orientation and proximity of the naturally occurring multimeric receptor. The bridging moiety can be an amino acid spacer peptide, an organic molecule, an Fe portion of a human immunoglobulin or an amphipathic helix, for example.

In another aspect, the invention includes antibodies produced by the above-described method. The antibodies so generated are characterized by the ability to bind to the naturally occurring receptor and by such binding initiate the biological activity of the receptor. The antibodies of the invention may be chimeric antibodies, humanized antibodies, monoclonal antibodies or polyclonal antibodies.

In still another aspect, the invention provides a recombinant polynucleotide sequence comprising a nucleotide sequence encoding the extracellular domain of a receptor molecule fused in frame to a nucleotide sequence encoding a specific proteolytic cleavage site, said cleavage sequence associated with a bridging moiety.

Yet a further aspect of the invention is the recombinant multimeric immunogen itself.

Additional aspects of this invention include a vector comprising a polynucleotide sequence described above under the control of suitable regulatory sequences capable of directing replication and expression of the polynucleotide sequence in a host cell, and a transformed host cell.

Still other aspects of the invention include therapeutic reagents comprising the antibodies produced by the method of this invention, as well as a method of treating a disease condition by administering a pharmaceutical composition of the invention.

Other aspects and advantages of the present invention are described further in the following detailed description of the preferred embodiments thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph illustrating the effects of the dimeric fusion protein EpoRFc and the monomeric protein mEpoR on erythropoietin stimulation of UT-7 Epo cells, which plots % positive control vs. concentration (ng/ml).

FIG. 2 is a graph illustrating the effects of the dimeric fusion protein EpoRFc and the monomeric protein mEpoR on erythropoietin stimulation of DA3Epowt cells, which plots % positive control vs. concentration (ng/ml).

FIG. 3 is a graph illustrating the effects of the dimeric fusion protein EpoRFc and the monomeric protein mEpoR on erythropoietin stimulation in an CFU-E assay, which plots % positive control vs. concentration (ng/ml).

FIGS. 4(A-B) is a bar graph demonstrating the binding of antibodies developed in response to immunization with the EpoRFc fusion protein 32D/Epo wt and parental 32D FIG. (4a) and UT-7EPO, cells, plotting % Isotype control log fluorescence vs. control (CTL) and supernatant designation.

FIG. 5 is a bar graph demonstrating the results of an UT7-EPO proliferation assay with three mAbs to EpoRFc, plotting % Epo maximum vs. dilutions of supernatants. The supernatant designations are listed above the bars.

FIG. 6 is a bar graph demonstrating the ability of 4 mAbs to EPORF_(c) to stimulate the proliferation and differentiation of human bone marrow progenitor cells to form red blood cell colonies (CFU-E), plotting Number of CFU-E vs. positive and negative EPO controls and supernatant dilutions. The supernatant designations are listed above the bars.

FIGS. 7A-7F is the DNA sequence [SEQ ID NO: 1] for plasmid mtalsEpoRFc containing the sequence encoding the EpoRFc fusion protein under control of a Drosophila S2 mtn promoter. Nucleotides 1 to 897 contain the promoter sequence. The EpoRFc fusion protein [SEQ ID NO: 2] is encoded by the following: nucleotides 898 to 1647 encode the EpoR extracellular domain protein; nucleotides 1648 to 1659 encode the Factor Xa cleavage sequence; nucleotides 1660 to 2361 encoding the human IgG₁ Fc sequence. The remainder of the sequence is derived from the plasmid parent. See Example 1.

FIGS. 8A-8E is the DNA sequence [SEQ ID NO: 3] of CosFcLink vector from which a KpnI/XbaI insert containing the IgG1 Fc region was obtained.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a reproducible and reliable composition and method for generating antibodies which demonstrate the agonist properties of the naturally occurring ligand of a receptor molecule. While, in principle, any purified preparation could be used to generate antibodies to a receptor, and from these some may be agonists, this invention provides a specific immunogen which corresponds to a multimeric form of a receptor in which the extracellular domains are in a similar disposition to that expected for receptors having two or more subunits on the surface of the cell.

I. The Recombinant Immunogen

The recombinant immunogen of the present invention consists of an extracellular domain of a selected receptor molecule which is involved in ligand binding via the interaction of more than one extracellular domain. The extracellular domain is spaced apart from a second extracellular receptor domain by a bridging moiety.

By "extracellular domain" is meant that portion of a receptor protein which is localized on the extracellular surface of a cell and which contributes to interaction and binding with its native ligand.

The receptor subunit which contributes the extracellular domain(s) of the immunogen may be any receptor subunit which accomplishes ligand binding via a homodimer of the extracellular domain, a heterodimer of two different subunits of the receptor's extracellular domain, or a multimer of subunits. Receptors which homodimerize upon ligand binding and thus may contribute extracellular domains to the recombinant immunogen include those for, inter alia, erythropoietin (EPO) and thrombopoietin (CMPL), G-CSF, M-CSF, TGF-a, EGF, neu, growth hormone, prolactin, placental lactogen, c-kit (stem cell factor receptor), p50 and p75 receptor subunits of TNFa, and TNFβ. Other receptors which are anticipated to dimerize based on homology to TNF and which can be included in this list are Fas, CD40, CD27, CD30, 4-1BB and OX40.

Similarly, receptors which are already in a homodimeric form on the cell surface, prior to ligand binding may also contribute the extracellular domain(s) to the immunogen. These latter receptors include, inter alia, insulin, IGF1 and IGF2, and PDGF. PDGF includes dimeric ligand made of two chains A and B and two receptor subunits a and b. Ligands and receptors can associate as homo- or heterodimers. Relaxin is also anticipated to be a dimeric receptor prior to ligand binding based on its homology to insulin and IGF.

Receptors which are formed by heterodimers of two different subunits may also be employed as contributors of extracellular domain(s) of one or both of the subunits to the recombinant. Such receptors include, inter alia, GM-CSF, IL-3, IL-5, IL-6, Oncostatin M, CNTF, LIF, NGF, FGF, IL-4, IL-13, IFNa, IFNβ, IFNg, TGFβ1, TGFβ2 and IL-12. Receptors, such as IL-3, which involve more than one subunit may respond to this method, if dimerization of one of the subunits is required for signal transduction.

Receptors which form other aggregations, such as trimers of IL-2 receptor subunits, may also be used as sources of extracellular domain(s) for the recombinant immunogen of this invention.

The extracellular domains of the selected receptor useful in the recombinant immunogen may be isolated and/or otherwise obtained by resort to the published and publicly available receptor sequences. Methods conventional in the art may be employed to isolate or synthesize the appropriate nucleotide sequences encoding these domains for further manipulation in the generation of the immunogen of this invention.

By the term "bridging moiety" is meant a peptide or non-peptide sequence that stably associates with itself and places the first extracellular domain and the second extracellular domain into functional proximity (i.e., a relationship between the two or more domains which mimics the three dimensional functional proximity of the domains in the naturally occurring multimeric receptor, during or prior to ligand binding. Preferably, the bridging moiety is of a sufficient size to bring together the membrane proximal regions (i.e., the regions closes to the transmembrane region) of the extracellular domain. The precise dimensions of the bridging region can be estimated from the relevant crystal structures, such as those for growth hormone and its receptor, or TNF and its receptor [see, e.g., DeVos et al., Science, 255:306 (1992)].

The suitability of a given "bridging moiety" can sometimes be evaluated empirically. For example, a dimeric form of a receptor which dimerizes upon binding of ligand is expected to have a higher affinity for ligand than a monomeric form of the extracellular domain of the receptor, if the bridging group is appropriate. This would be evidenced either by direct binding studies of ligand to monomeric and dimeric receptor, or by the relative ability of the two forms of receptor to neutralize the biological activity of the ligand. For example, FIG. 1 shows the ability of dimeric EpoRFc to neutralize Epo activity about 100 times more effectively than monomeric EpoR.

An example of a bridging moiety is an amino acid spacer sequence (e.g., between 1 to 10 amino acids in length and optionally encoding a cleavage site) fused to a dimerization or oligomerization domain which permits the formation of dimers or oligomers, respectively. In the following example, for instance, a spacer encoding the Factor Xa cleavage site is part of the bridging moiety; and the dimerization domain is the hinge CH2CH3 region of a human IgG1. This IgG component consists of the CH2 and CH3 domains and the hinge region of IgG1 including cysteine residues contributing to inter-heavy chain disulfide bonding, for example residues 11 and 14 of the IgG1 hinge region [see, e.g., B. Frangione, Nature, 216: 939-941, (1967)]. Preferably the IgG1 component consists of amino acids corresponding to residues 1-4 and 6-15 of the hinge, 1-110 of CH2 and 1 -107 of CH3 of IgG1 described by J. Ellison et al., Nucleic Acids Res., 10: 4071-4079 (1982). Residue 5 of the hinge is changed from cysteine in the published IgG1 sequence to alanine by alteration of TGT to GCC in the nucleotide sequence.

The bridging moiety can also be an Fc portion of any human immunoglobulin with an intact hinge CH2CH3 region, including those derived from IgG, IgE, IgM, IgA and IgG₄. Still another suitable bridging moiety is an amino acid spacer fused to the C terminal domain of the TNF-like receptor of the shope fibroma poxvirus [C. A. Smith al., BBRC, 176: 335-342 (1991)]. The bridging moiety may also be an a dimerization domain like an amphipathic helix, such as a leucine zipper [see, e.g., P. Pack et al., Biochem., 31(6): 1579-1584 (Feb. 18, 1992)]. The bridging moiety may also be alkaline phosphatase.

Still other desirable embodiments of the bridging moiety are organic molecules which can functionally associate the receptor extracellular domains as desired. Such organic molecules may be selected from among such molecules known to associate peptide sequences to each other for other biological uses, e.g., bifunctional cross-linkers, such as carbodiimide, glutaraldehyde and DSS, BS3, and other which may be obtained from several commercial sources. However, these associations may require combination with specific target sequences for cross-linking, e.g., an exposed Cys or His for nickel chelate, to achieve the appropriate three dimensional disposition of receptor subunits. Choice of an appropriate cross-linker can be determined by comparison to known crystal structures of homologous receptors.

The suitability of a particular peptide or non-peptide entity as a bridging moiety may be functionally assessed in a receptor ligand binding assay. The suitability of the bridging moiety may be determined if the recombinant immunogen binds the receptor's intended ligand with greater affinity than does the monomeric sequence of the receptor extracellular domain. Ligand binding assays for the selected receptors are known to those of skill in the art and maybe readily selected without undue experimentation. See, for example, the EpoR ligand assays described in Komatsu et al., Blood, 82:456-464 (1993); Miura et al., Mol. Cell. Biol., 11:4895-4902 (1991): Witthuhn et al., Cell, 74:227-236 (1993).

Another bridging moiety or linker may be prepared by mutagenesis of a receptor in the membrane proximal domain to create unpaired Cys, which can disulfide bond to create a dimeric receptor. Such mutations can be evaluated for appropriateness by observing whether the full length receptor containing such a mutation is able to constitutively activate the ligand's activity upon transfection into suitable target cells (e.g., EpoR mutations) [see, e.g., Watowich et al., Proc. Natl. Acad. Sci., USA., 89:2140-2144 (1992)].

Thus, for example, the bridging moiety of the recombinant immunogen can associate two identical extracellular domains into an immunogen that mimics a homodimeric receptor. Alternately, for example, the bridging moiety can associate two different extracellular domains of subunits of one receptor into an immunogen that mimics a heterodimeric receptor. For example, for the heterodimeric association of different subunits from a heterodimeric receptor, a different bridging moiety could be used for each receptor subunit. The bridging moiety for a heterodimeric receptor is preferably a domain that cannot associate with itself, but which preferentially associates with a second domain. Thus, the first bridging moiety can be a CH1 region of a light chain of a selected immunoglobulin. Its complementary bridging moiety is the CH1 region of the heavy chain of the same immunoglobulin or the entire Fc region including the CH1, hinge, CH2, and CH3 regions of the heavy chain. It is also anticipated that various bridging entities may be employed in preparing other multimeric immunogens, e.g., trimers, by associating three identical domains or three extracellular domains from one, two or three subunits of a single receptor. It is presently preferred to use an Fc portion of an immunoglobulin as a bridging moiety to associate the extracellular receptor domains, as disclosed in Example 1 below.

II. Construction and Preparation of the Recombinant Immunogen

The present invention also provides the nucleic acid sequences encoding the recombinant immunogens described above. The nucleotide sequences encoding the extracellular domains of the receptors useful in the immunogens may be obtained from known receptor sequences by conventional means [see J. Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd ed., Cold Spring Harbor Laboratory (1989)]. For example, the nucleotide sequences which form the immunogen of the invention may be isolated by conventional uses of polymerase chain reaction or conventional genetic engineering cloning techniques. Alternatively, these sequences may be constructed using chemical synthesis techniques.

Optionally, a nucleotide sequence which encodes a peptide sequence which provides an enzymatic cleavage site (of which many are well known in the art) is fused in frame to the extracellular domain nucleotide sequence prior to its association with the dimerization or oligomerization domain of the bridging moiety. This facilitates cleavage of the extracellular domain from the bridging moiety following expression.

According to the invention, the nucleic acid sequences encoding the extracellular domains may be modified as desired. It is within the skill of the art to obtain other polynucleotide sequences encoding these receptor domains useful in the invention. Such modifications at the nucleic acid level include, for example, modifications to the nucleotide sequences which are silent or which change the amino acids, e.g. to improve expression or secretion. Such modifications include amino terminal, carboxy terminal or internal deletions of the nucleotide sequences, as desired.

Where the bridging moiety is an amino acid sequence, the nucleotide sequence encoding it is also obtained conventionally and fused to the extracellular domain sequence directly or via a cleavage site or via additional sequence intended as a spacer. For example, where the bridging moiety is an Fc portion of a human immunoglobulin with intact hinge CH₂ CH₃ region, the nucleotide sequence encoding the Fc region is obtained from known antibody sequences, prepared by conventional techniques and fused in frame to the receptor sequences or to the sequence providing the enzymatic cleavage site.

To produce recombinant immunogens of this invention, a DNA sequence of the invention encoding the extracellular receptor domain, is fused in frame to an optional cleavage site and further fused to a nucleotide sequence encoding a peptide bridging moiety. Preparation of the nucleic acid sequences may be carried out chemically, enzymatically, or by a combination of the two methods, in vitro or in vivo as appropriate. Thus, the DNA sequences may be prepared by the enzymatic ligation of appropriate DNA fragments, by conventional methods such as those described by D. M. Roberts et al., Biochem., 24:5090-5098 (1985). The DNA fragments may be obtained by digestion of DNA containing the required sequences of nucleotides with appropriate restriction enzymes, by chemical synthesis, by enzymatic polymerization on DNA or RNA templates, or by a combination of these methods. These methods are generally provided by the commercial supplier of the reagents.

For example, digestion with restriction enzymes may be performed in an appropriate buffer at a temperature of 20-70° C., generally in a volume of 50 ul or less with 0.1-10 ug DNA. Enzymatic polymerization of DNA may be carried out in vitro using a DNA polymerase such as DNA polymerase I (Klenow fragment) in an appropriate buffer containing the nucleoside triphosphates dATP, dCTP, dGTP and dTTP as required at a temperature of 10-37° C., generally in a volume of 50 ul or less. Enzymatic ligation of DNA fragments may be carried out using a DNA ligase such as T4 DNA ligase in an appropriate buffer at a temperature of 4° C. to ambient, generally in a volume of 50 ul or less. The chemical synthesis of the DNA sequence or fragments may be carried out by conventional phosphotriester, phosphite or phosphoramidite chemistry, using solid phase techniques such as those described in "Chemical and Enzymatic Synthesis of Gene Fragments--A Laboratory Manual" (ed. H. G. Gassen and A. Lang), Verlag Chemie, Weinheim (1982), or in other scientific publications, for example M. J. Gait el al., Nucleic Acids Res., 10: 6243 (1982) and others. Preferably an automated DNA synthesizer is employed. The DNA sequence is preferably prepared by ligating two or more DNA molecules which together comprise a DNA sequence encoding the compound. The DNA molecules may be obtained by the digestion with suitable restriction enzymes of vectors carrying the required coding sequences or by use of polymerase chain reaction technology. The precise structure of the DNA molecules and the way in which they are obtained depends upon the structure of the desired product. The design of a suitable strategy for the construction of the DNA molecule coding for the recombinant immunogen is a routine matter for one skilled in the art.

Once the nucleotide sequence encoding the recombinant immunogen is designed, it is inserted into a suitable expression system. Systems for cloning and expression of a selected protein in a desired microorganism or cell, including, e.g., E. coli, Bacillus, Streptomyces, mammalian, insect, and yeast cells, are known and available from private and public laboratories and depositories and from commerical vendors.

Desirably, a recombinant molecule or vector is constructed in which the polynucleotide sequence encoding the immunogen is operably linked to a heterologous expression control sequence permitting expression of the human protein. Numerous types of appropriate expression vectors are known in the art for eukaryotic (including human) protein expression, by standard molecular biology techniques. Such vectors may be selected from among conventional vector types including mammalian, insects, e.g., baculovirus expression, Drosophila S2 cell, or yeast, fungal, bacterial or viral expression systems. Other appropriate expression vectors, of which numerous types are known in the art, can also be used for this purpose. Methods for obtaining such expression vectors are well-known. See, for example, Sambrook et al., cited above; Miller et al., Genetic Engineering, 8:277-298 (Plenum Press 1986) and Johansen et al., Genes and Develop., 3:882-889 (1989)].

Suitable host cells or cell lines for transfection by this method include mammalian cells, such as Human 293 cells, Chinese hamster ovary cells (CHO), the monkey COS-1 cell line or murine 3T3 cells derived from Swiss, Balb-c or NIH mice may be used. Another suitable mammalian cell line is the CV-1 cell line. Still other suitable mammalian host cells, as well as methods for transfection, culture, amplification, screening, and product production and purification are known in the art. [See, e.g., Gething and Sambrook, Nature, 293:620-625 (1981), or alternatively, Kaufman et al., Mol. Cell. Biol., 5 (7):1750-1759 (1985 ) or Howley et al., U.S. Pat. No. 4,419,446].

Similarly bacterial cells are useful as host cells for the present invention. For example, the various strains of E. coli (e.g., HB101, MC1061, and strains used in the following examples) are well-known as host cells in the field of biotechnology. Various strains of B. subtilis, Pseudomonas, Streptomyces, other bacilli and the like may also by employed in this method.

Many strains of yeast cells known to those skilled in the art are also available as host cells for expression of the polypeptides of the present invention. Other fungal cells may also be employed as expression systems. Alternatively, insect cells such as Spodoptera frugipedera (Sf9) of Drosophila S2 may be used.

Thus, the present invention provides a method for producing a recombinant novel multimeric receptor immunogen which involves transfecting a host cell with at least one expression vector containing a recombinant polynucleotide as above-described under the control of a transcriptional regulatory sequence, e.g. by conventional means such as electroporation. The transfected host cell is then cultured under suitable conditions that allow expression of the product of the recombinant polynucleotide. During expression, the recombinant multimeric immunogen if formed in the cell by the association of the bridging moiety with itself. The expressed multimeric protein is then recovered, isolated, and optionally purified from the culture medium (or from the cell, if expressed intracellularly) by appropriate means known to one of skill in the art.

To generate a heterodimeric receptor immunogen, a vector is designed as above to carry a first receptor subunit which is fused to, e.g., the CH1 region of the light chain. A vector is also designed to carry the second, different subunit of the receptor fused to e.g., the heavy chain sequence (e.g., CH1 region or the entire Fc region of the same Ig that contributes the light chain CH1, as described above). Alternatively both sequences could be present on a single vector. The vectors are prepared as described above. However, for a heterodimeric receptor immunogen, the host cell must be co-transfected with both receptor-bridging moiety polynucleotide sequences. Expression of both sequences in the host cell causes the light chain CH1 and heavy chain CH1, or light chain CH1 and heavy chain Fc sequences to associate only complementarily (e.g., with each other not with their identical counterparts in the cell). Heterodimeric receptor immunogens are thereby formed in the manner of a "Fab"-like fragment or an antibody-like fragment, respectively.

Once expressed, the recombinant immunogen (e.g., homodimeric or heterodimeric) may be isolated following cell lysis in soluble form, or may be extracted using known techniques, e.g., in guanidine chloride. If the protein is secreted, it can be isolated from culture supernatant and purified. With an Fc bridging moiety, Protein A or Protein G Sepharose may be used to purify the immunogen. Where the immunogen is a receptor subunit sequence fused to a peptide, epitope, a specific monoclonal antibody mAb to the peptide epitope can be used to purify the immunogen.

Another method of producing the novel multimeric receptor immunogen involves directly injecting the monomeric recombinant DNA (as, e.g., "naked DNA") into mice or rabbits intramuscularly. The multimeric receptor thus assembles in vivo, where it acts as an immunogen. See, e.g., Cohen, Science, 259:1691-92 (1993); E. F. Fynan et al., Proc. Natl. Acad. Sci., USA, 90:11478-11482 (1993).

Association of a nucleotide sequence encoding the selected receptor extracellular domain and its optional cleavage site with a non-peptide bridging moiety may be by conventional covalent or ionic bonds, using conventional chemical linking agents. If the association is non-covalent, then cross-linking must occur wither after purification or in freshly isolated cells prior to purification. Alternatively, the opportunity to cross-link could be enhanced by adding ligand to the receptor sequences to bring them into proximity to each other, and cross-linking agent and bridging moiety, and dissociate ligand by a conventional technique, e.g., low pH. The dimeric receptor could then be purified.

III. The Method of the Invention

The recombinant immunogens of this invention are thus useful as antigens for the development of anti-receptor antisera and antibodies to the multimeric receptor domain immunogen. Specific antisera and polyclonal antibodies may be generated by employing the recombinant multimeric immunogen as an immunogen using known techniques. See, Sambrook, cited above, Chapter 18, generally, incorporated by reference. Additionally, polyclonal antibodies and antisera may be generated to the immunogen formed in vivo following administration of the naked DNA.

The polyclonal antibodies developed in the immunized animal may be isolated from the animal's plasma, peripheral blood or other tissue in a conventional manner. Antibodies thus isolated may be employed in the methods described below for generation of mAbs, humanized and chimeric antibodies of the invention.

For example, monoclonal antibodies of the invention may be produced by conventional methods, including the Kohler and Milstein hybridoma technique, in which spleen cells from an immunized animal are fused with immortalized cells to create hybridoma cell lines which secrete a single mAb. Each hybridoma is then screen with a simple binding assay to detect agonist properties.

Other types of anitbodies may be designed based on the agonist mAbs so identified. For example, recombinant techniques, such as described by Huse et al., Science, 246:1275-1281 (1988), or any other modifications thereof known to the art may be employed to generate antibodies. Thus, also encompassed within this invention are methods for generating humanized and chimeric agonist antibodies by employing the CDRs from the agonist antibodies produced as described above. Methods of identifying suitable human framework regions and modifying a mAb of the invention to contain same to produce a humanized or chimeric antibody of the invention, are well known to those of skill in the art. See, e.g., E. Mark and Padlin, "Humanization of Monoclonal Antibodies", Chapter 4, The Handbook of Experimental Pharmacology, Vol. 113, The Pharmacology of Monoclonal Antibodies, Springer-Verlag (June, 1994). Other types of recombinantly-designed antibodies are also encompassed by this invention.

As used in this specification and the claims, the following terms are defined as follows:

"Altered antibody" refers to a protein encoded by an altered immunoglobulin coding region, which may be obtained by expression in a selected hose cell. Such altered antibodies are engineered antibodies (e.g., chimeric, humanized, reshaped human or reconstituted human antibodies) or antibody fragments lacking all or part of an immunoglobulin constant region, e.g., Fv, Fab, or F(ab')₂ and the like.

"Altered immunoglobulin coding region" refers to a nucleic acid sequence encoding the altered antibody of the invention. When the altered antibody is a "reshaped human antibody", the sequences that encode the complementarity determining regions (CDRs) from a donor human immunoglobulin are individually inserted into a first immunoglobulin partner comprising human variable framework or as components of a variable region gene sequence attached to human constant sequences. If desired, the first immunoglobulin partner is operatively linked to a second fusion partner.

"First immunoglobulin partner" refers to a nucleic acid sequence encoding a human framework or human immunoglobulin variable region in which the native (or naturally-occurring) CDR-encoding regions are replaced by the CDR-encoding regions of a donor human antibody. The human variable region can be an immunoglobulin heavy chain, a light chain (or both chains), an analog or functional fragments thereof. Such CDR regions, located within the variable region of antibodies (immunoglobulins) can be determined by known methods in the art. For example Kabat et al. (Sequences of Proteins of Immunological Interest, 4th Ed., U.S. Department of Health and Human Services, National Institutes of Health (1987)) disclose rules for locating CDRs. In addition, computer programs are known which are useful for identifying CDR regions/structures.

"Second fusion partner" refers to another nucleotide sequence encoding a protein or peptide to which the first immunoglobulin partner is fused in frame or by means of an optional conventional linker sequence (i.e., operatively linked). Preferably the fusion partner is an immunoglobulin gene and when so, it is referred to as a "second immunoglobulin partner". The second immunoglobulin partner may include a nucleic acid sequence encoding the entire constant region for the same (i.e., homologous--the first and second altered antibodies are derived from the same source) or an additional (i.e., heterologous) antibody of interest. It may be an immunoglobulin heavy chain or light chain (or both chains as part of a single polypeptide). The second immunoglobulin partner is not limited to a particular immunoglobulin class or isotype. In addition, the second immunoglobulin partner may comprise part of an immunoglobulin constant region, such as found in a Fab, or F(ab)₂ (i.e., a discrete part of an appropriate human constant region or framework region). A second fusion partner may also comprise a sequence encoding an integral membrane protein exposed on the outer surface of a host cell, e.g., as part of a phage display library, or a sequence encoding a protein for analytical or diagnostic detection, e.g., horseradish peroxidase, β-galactosidase, etc.

The terms Fv, Fc, Fd, Fab, or F(ab')₂ are used with their standard meanings (see, e.g., Harlow et al., Antibodies A Laboratory Manual, Cold Spring Harbor Laboratory, (1988)).

As used herein, an "engineered antibody" describes a type of altered antibody, i.e., a full-length synthetic antibody (e.g., a chimeric, reconstituted human, or reshaped human antibody as opposed to an antibody fragment) in which a portion of the light and/or heavy chain variable domains of a selected acceptor antibody are replaced by analogous parts from one or more donor antibodies which have specificity for the selected epitope. For example, such molecules may include antibodies characterized by an engineered heavy chain associated with an unmodified light chain (or chimeric light chain), or vice versa. Engineered antibodies may also be characterized by alteration of the nucleic acid sequences encoding the acceptor antibody light and/or heavy variable domain framework regions in order to retain donor antibody binding specificity. These antibodies can comprise replacement of one or more CDRs (preferably all) from the acceptor antibody with CDRs from a donor antibody described herein.

A "chimeric antibody" refers to a type of engineered antibody which contains naturally-occurring variable region (light chain and heavy chains) derived from a donor antibody in association with light and heavy chain constant regions derived from an acceptor antibody from a heterologous species.

A "humanized antibody" refers to a type of engineered antibody having its CDRs derived from a non-human donor immunoglobulin, the remaining immunoglobulin-derived parts of the molecule being derived from one (or more) human immunoglobulin(s). In addition, framework support resides may be altered to preserve binding affinity (see, e.g., Queen et al., Proc. Nat'l. Acad. Sci. USA, 86:10029-10032 (1989), Hodgson et al., Bio/Technology, 9:421 (1991).

The term "reconstituted human antibody" refers to an antibody in which a Fab is converted into a full length Mab by cloning the heavy chain of the Fab into a human Ig constant region comprising the hinge region and CH-2 and CH-3 domains. Preferably the constant region is one of the IgG isotypes IgG1-IgG4 or variants thereof such as PE muatations. A reconstituted human antibody also includes variants of the processes, mature NH₂ terminal regions of the light or heavy chain are altered to conform with the predicted germ line parent sequence.

The term "donor antibody" refers to an antibody (monoclonal, or recombinant) which contributes the nucleic acid sequences of its variable regions, CDRs, or other functional fragments or analogs thereof to a first immunoglobulin partner, so as to provide the altered immunoglobulin coding region and resulting expressed altered antibody with the antigenic specificity and neutralizing activity characteristic of the donor antibody. One donor antibody suitable for use in this invention is 1C8.

The term "acceptor antibody" refers to an antibody (monoclonal, or recombinant) from a source genetically unrelated to to the donor antibody, which contributes all (or any portion, but preferably all) of the nucleic acid sequences encoding its heavy and/or light chain framework regions and/or its heavy and/or light chain constant regions to the first immunoglobulin partner. Preferably a human antibody is the acceptor antibody.

"CDRs" are defined as the complementarity determining region amino acid sequences of an antibody which are the hypervariable regions of immunoglobulin heavy and light chain. See, e.g., Kabat et al., Sequences of Proteins of Immunological Interest, 4th Ed., U.S. Department of Health and Human Services, National Institutes of Health (1987). There are three heavy chain and three light chain CDRs (or CDR regions) in the variable portion of an immunoglobulin. Thus, "CDRs" as used herein refers to all three heavy chain CDRs, or all three light chain CDRs (or both all heavy and all light chain CDRs, if appropriate). CDRs provide the majority of contact residues for the binding of the antibody to the antigen or epitope. CDRs of interest in this invention are derived from donor antibody variable heavy and light chain sequences, and include analogs of the naturally occurring CDRs, which analogs also share or retain the same antigen binding specificity and/or neutralizing ability as the donor antibody from which they were derived.

By "sharing the antigen binding specificity or neutralizing ability" is meant, for example, that although antibody such as 1C18 may be characterized by a certain level of antigen affinity, a CDR encoded by a nucleic acid sequence of 1C8 in an appropriate structural environment may have a lower, or higher affinity. It is expected that CDRs of 1C18 in such environments will nevertheless recognize the same epitope(s) as in 1C8. A "functional fragment" is a partial heavy or light chain variable sequence (e.g., minor deletions at the amino or carboxy terminus of the immunoglobulin variable region) which retains the same antigen binding specificity and/or neutralizing ability as the antibody from which the fragment was derived.

An "analog" is an amino acid sequence modified by at least one amino acid, wherein said modification can be chemical or a substitution or a rearrangement of a few amino acids (i.e., no more than 10), which modification permits the amino acid sequence to retain the biological characteristics, e.g., antigen specificity and high affinity, of the unmodified sequence. For example, (silent) mutations can be constructed, via substitutions, when certain endonuclease restriction sites are created within or surrounding CDR-encoding regions.

Analogs may also arise as allelic variations. An "allelic variation or modification" is an alteration in the nucleic acid sequence encoding the amino acid or peptide sequences of the invention. Such variations or modifications may be due to degeneracy in the genetic code or may be deliberately engineered to provide desired characteristics. These variations or modifications may or may not result in alterations in any encoded amino acid sequence.

The term "effector agents" refers to non-protein carrier molecules to which the altered antibodies, and/or natural or synthetic light or heavy chains of the donor antibody or other fragments of the donor antibody may be associated by conventional means. Such non-protein carriers can include conventional carriers used in the diagnostic field, e.g., polystyrene or other plastic beads, polysaccharides, e.g., as used in the BIAcore (Pharmacia) system, or other non-protein substances useful in the medical field and safe for administration to humans and animals. Other effector agents may include a macrocycle, for chelating a heavy metal atom, or radioisotopes. Such effector agents may also be useful to increase the half-life of the altered antibodies, e.g., polyethylene glycol.

Also provided by the invention are human antibodies derived from human hybridomas, antibodies obtained by rescue from transgenic mice expressing human Ig domains, and antibodies make in primates. Any other modifications which are known to be useful to prepare mAbs as pharmaceutical agents may also be made to the antibodies of this invention.

Without wishing to be bound by theory, it is anticipated that the recombinant immunogens of this invention have configurations mimicking the form of the multimeric receptor on the cell surface. Thus, these immunogens generate a higher frequency of antibodies which crosslink the multiple receptor subunits in a manner similar to that of the naturally occurring ligand and thereby are more likely than randomly obtained antibodies to be agonists of the receptor.

IV. Utilities

Polyclonal antisera, monoclonal antibodies and other antibodies of this invention, which bind to the novel immunogen as the antigen and can function as agonists are useful in substantially the same manner as is the naturally occurring ligand of the receptor. For example, an agonist antibody developed to the exemplary erythropoietin receptor dimeric fusion protein described in Example 2 may be used in therapeutic, diagnostic and research methods in which the ligand, erythropoietin, is useful. These antibodies may be used as research tools and as components for separation of the receptor proteins from other contaminants of living tissue, for example, are also contemplated for these antibodies.

Agonist antibodies to the receptor would have the same therapeutic utility as the natural ligand, but would have the advantage of longer half-life and hence prolonged activity in vivo. These agonists can thus be employed to activate the biological activity which results from receptor/ligand binding. Thus, these agonist antibodies are useful in the treatment of diseases in which the interaction of the receptor and its ligand is part of a biochemical cascade of events leading to a desired response. The advantages of such agonist antibodies include the ability to administer lower dosages of antibody than ligand, easier and less frequent administration of a pharmaceutic based on the agonist antibody, as well as easier purification. Agonist antibodies may demonstrate a different profile of activity in vivo than the non-agonist antibodies due to a different distribution.

Compositions and methods useful for the treatment of conditions associated with abnormal receptor or ligand levels are provided. The present invention provides pharmaceutical compositions useful in the treatment of: anemia associated with chronic renal failure; anemia associated with AIDS; pre-dialysis patients; patients in need of pre- and/or post surgery hematocrit boosting; cancer patients undergoing hematocrit decreasing radiation or chemotherapy; rheumatoid arthritis and sickle cell anemia. These compositions contain a therapeutically effective amount of an agonist antibody of this invention and an acceptable pharmaceutical carrier. As used herein, the term "pharmaceutical" includes veterinary applications of the invention. The term "therapeutically effective amount" refers to that amount of a receptor agonist antibody, which is useful for alleviating a selected condition. Also provided are compositions and methods for inhibiting receptor activity in order to ameliorate an undesired response.

The receptor agonist antibodies of the invention can be formulated into pharmaceutical compositions and administered in the same manner as described for mature proteins [see, e.g., International Patent Application, Publication No. WO 90/02762 (Mar. 22, 1990)]. These therapeutic compositions of the invention may be administered to mimic the effect of the normal receptor ligand. These compositions may contain a pharmaceutically acceptable carrier. Suitable carries are well known to those of skill in the art and include, for example, saline. Alternatively, such compositions may include conventional delivery systems into which protein of the invention is incorporated. Optionally, these compositions may contain other active ingredients, e.g., chemotherapeutics.

Thus, the invention also provides improved methods of treating a variety of disorders in which receptor/ligand interactions are implicated, e.g., inflammation, autoimmune disorders, etc. For example, an agonist antibody developed to a dimeric EpoR of this invention can be employed to treat acute renal failure, anemia, AIDS, and any disorder which the ligand erythropoietin can be used for treatment, e.g., for cancer chemotherapy. Similarly, an agonist antibody developed to a dimeric TopR receptor may be employed to treat conditions of low platelet count, i.e., patients undergoing chemotherapy for cancer, etc. An agonist antibody developed to the G-CSF dimeric receptor of this invention is useful to stimulate the polymorphonuclear cells, thereby for the treatment of conditions characterized by neutropenia, e.g., cancer chemotherapy, etc.

The invention encompasses methods of administering therapeutically effective amounts of a antibody or pharmaceutical compositions of the invention to a patient. The dose, timing and mode of administration of these therapeutic or gene therapy compositions may be determined by one of skill in the art, and may be less than or equal to the amounts of the ligand known to be administered for similar conditions. Such factors as the disease being treated, the age, physical condition, and the level of the receptor detected by the diagnostic methods described above, may be taken into account in determining the dose, timing and mode of administration of the therapeutic compositions of the invention. Generally, where treatment of an existing disorder is indicated, a therapeutic composition of the invention is preferably administered in a site-directed manner and is repeated as needed. Such therapy may be administered in conjunction with conventional therapies for such conditions.

Generally, an agonist antibody of the invention is administered in an amount between about 0.01 ng/kg body weight to about 1 g/kg and preferably about 0.01 ng/kg to 100 mg/kg per dose. Preferably, these pharmaceutical compositions are administered to human or other mammalian subjects by injection. However, administration may be by any appropriate internal route, and may be repeated as needed, e.g., as frequently as one to three times daily for between 1 day to about three weeks to once per week or once biweekly. Preferably, the agonist antibody is administered less frequently than is the ligand, when it is used therapeutically.

Optionally, the pharmaceutical compositions of the invention may contain other active ingredients or be administered in conjunction with other therapeutics. Suitable optional ingredients or other therapeutics include those conventional for treating conditions of this nature, e.g. other anti-inflammatories, diuretics, and immune suppressants, among others.

According to the methods of this invention, and as described in detail in the following examples, antibodies were generated to the erythropoietin receptor (EpoR), which mimic the agonist properties of erythropoietin. The following examples illustrate the construction and expression of exemplary multimeric receptor proteins of the invention. These examples are illustrate only and do not limit the scope of the invention.

EXAMPLE 1 Multimeric EpoR Antigen

A dimeric antigen of this invention was designed by fusing the extracellular domain of the erythropoietin receptor via an amino acid linker to the Fc portion of a human immunoglobulin, and expressing the fusion protein in a suitable host cell.

Using the following primers sets based on the published nucleotide sequence of EpoR (Jones et al., Blood, 76:31-35 (1990)), the extracellular domain of the EpoR was amplified via PCR from a human fetal liver cDNA library (Clontech).

One primer was selected from: 5' GT ATC ATG GAC CAC CTC GGG GCG TCC CTC TGG CCC CAG 3' [SEQ ID NO: 4] AND 5' ATG GAC CAC CTC GGG GCG TCC CTC TGG CCC CAG 3' [SEQ ID NO: 5]. A second primer was selected from: 3' GGA GAC GGG GGG TCG ATA CAC CGA ACG AGA ATC CTG TG 5' [SEQ ID NO: 6] and 3' GGA GAC GGG GGG TCG ATA CAC CGA ACG AGA ATC 5' [SEQ ID NO: 7]; 3' CAC AGC GAC GAC TGC GGA TCG CTG GAC CTG GGG atc act ga 5' [SEQ ID NO:8] and 3' CAC AGC GAC GAC TGC GGA TCG CTG GAC CTG GGG gtc 5' [SEQ ID NO: 9].

The resulting 250 bp DNA fragment so isolated was cloned into the vector PCR2000 (Invitrogen) and sequenced. The EpoR fragment was found to encode amino acids 1-250 [SEQ ID NO: 2] of the extracellular domain of the human EpoR [Jones et al., cited above; SWISSPROT Accession number P19235].

An SpeI/XbaI fragment was isolated from the PCR2000-derived vector by digestion containing this EpoR insert, nucleotide 898 to 1647 of SEQ ID NO: 1. The insert was then cloned into the Drosophila S2 vector mtal [see, European Patent No. 290,261 B, published Nov. 9, 1988] at the equivalent linker sites, SpeI and XbaI. The resulting plasmid vector, pS2EpoR contains the EpoR extracellular domain gene insert under the control of the Drosophila copper metallothionein (mtn) promoter [Johansen et al., Genes and Development, 3:882-889 (1989); Angelichio et al., Nucl. Acid Res., 19:5037-5043 (1991)].

The plasmid pS2EpoR was digested with BssH2 and XbaI and a C terminal fragment of the EpoR sequence was removed by this digestion. A plasmid containing the whole EpoR gene fused to a bridging moiety was then prepared by cloning the following three fragments:

(1) a large BssH2/XbaI fragment from the above digestion;

(2) a synthetic BssH2/KpnI linker, which spanned nucleotide 1561 to nucleotide 1659 of SEQ ID NO: 1, which encoded the C terminus of the EpoR extracellular domain, aa 22 to 250 of SEQ ID NO: 2, linked in frame to the four amino acid recognition sequence for protease Factor Xa cleavage (IleGluGlyArg) [amino acids 251 to 254 of SEQ ID NO: 2], and

(3) a KpnI/XbaI fragment containing the human IgG1 Fc region, spanning nucleotide 1660 to the XbaI site which appears at nucleotides 2371-2376 of SEQ ID NO: 1 [see, also Johansen et al., J. Biol. Chem., 270:9459-9471 (1995)]. This KpnI/XbaI fragment was constructed as follows:

Human IgG1 cDNA encoding CH1, the hinge, CH2 and CH3 described by J. Ellison et al., Nucleic Acids Res., 10: 4071-4079 (1982) was cloned from the human IgG plasma cell leukemia ARH-77 (American Type Tissue Collection), using RT-PCR. This cDNA was fully sequenced to confirm identity with the published sequence [see, International patent publication WO 92/00985]. This sequence was inserted into a pUC18 vector (pUC18-Fc). This vector was digested with KpnI and SacII, deleting the CH1, hinge and part of CH2. The deleted region was replaced with a PCR amplified fragment containing the hinge-CH2 region as follows.

Using the following PCR primers: 5'TCG AGC TCG GTA CCG AGC CCA AAT CGG CCG ACA AAA CTC ACA C 3' [SEQ ID NO: 10] and 5' GTA CTG CTC CTC CCG CGG CTT TGT CTT G 3' [SEQ ID NO: 11], a DNA fragment containing the hinge-CH2 region was amplified from pUC18-Fc, digested with KpnI and SacII, gel purified and cloned back into the KpnI/SacII digested pUC18-Fc vector. The Cys, which occurs at position 230 [Kabat numbering; Kabat et al., "Sequences of Proteins of Immunological Interest, 5th Edition, US Department of Health and Human Services, NIH Publication No. 91-3242 (1991); this is also residue 5 of the hinge of the IgG1 heavy chain; residue 261 of SEQ ID NO: 2] was altered to an Ala through a TGT to GCC substitution in the nucleotide sequence to avoid having the unpaired Cys present which is usually involved in light chain-heavy chain crosslinking.

An altered DNA sequence in one of the PCR primers introduced a unique KpnI site at the 5' end of the hinge. The resulting plasmid was called pUC18Fcmod, and the junctions and PCR amplified region were sequenced for confirmation.

The entire hinge-CH2--CH3 insert in pUC18-Fcmod was removed in a single DNA fragment with KpnI and XbaI, gel purified, and ligated into SFcR1Cos4 cut with KpnI and XbaI to create COSFc. SFcR1Cos4 is a derivative of pST4DHFR [K. Deen et al, Nature, 331: 82 (1988)] and contains the soluble Fc receptor type I (sFcR1) inserted between the cytomegalovirus (CMV) promoter and bovine growth hormone (BGH) polyadenylation regions, and also contains the dihydrofolate reductase (DHFR) cDNA inserted between the b-globin promoter and SV40 polyadenylation regions, an SV40 origin of replication, and an ampicillin resistance gene for growth in bacteria.

Cutting the vector with KpnI and XbaI removes the sFcR1 coding region, so that the COSFc vector contains the hinge-CH2--CH3 region inserted between the CMV promoter and BGH polyA regions. The COSFcLink vector was made from COSFc by inserting an oligonucleotide linker at the unique EcoRI site of the vector, which recreates this EcoRI site, and also introduces BstEII, PstI and EcoRV cloning sites. The oligonucleotides used were:

5' AATTCGGTTACCTGCAGATATCAAGCT 3' [SEQ ID NO: 12] and

3' CGGAATCCACGTCTATAGTTCGATTAA 5' [SEQ ID NO: 13].

The junction was sequenced to confirm orientation in the vector. The size of the final vector is 6.37 kb and is reported as SEQ ID NO: 3. The KpnI/XbaI fragment used in the dimeric immunogen described herein was obtained from COSFcLink.

The resulting plasmid DNA construct containing the three fragments described above was called pmtalsEpoRFc [SEQ ID NOS: 1 and 2]. The plasmid sequence contains the heterologous fusion sequence comprising an intact EpoR extracellular domain encoding amino acids 1-250 of SEQ ID NO: 2 linked via a four amino acid linker (aa 251-254 of SEQ ID NO: 2) to a human IgG1 Fc region (aa 255 to 488 of SEQ ID NO: 2). In the plasmid, the fusion sequence was under the control of the mtn promoter, described above.

Plasmid pmtalsEpoFc was cotransfected into Drosophila S2 cells with a vector encoding hygromycin resistance [see, EP No. 290,261B, cited above]. Stable co-transfectants were selected in hygromycin, and expression of the EpoR induced by Cu2SO₄ according to published protocols [Johansen et al., cited above; Angelichio et al., cited above].

The co-transfected cells secreted the EpoRFc protein as a dimeric molecule due to the natural affinity of the Fc sequence for itself. Under reducing conditions in SDS-PAGE, the EpoRFc protein ran as a monomer. The dimeric protein was purified from Drosophila medium by passage over a Protein A Sepharose column.

To obtain the monomeric EpoR extracellular protein apart from its Fc fusion, the EpoRFc fusion protein is treated as follows: EpoR-Fc was dialyzed into 20 mM Tris, 100 mM NaCl, 2 mM CaCl₂, pH 8. Factor Xa (New England Biolabs) was added at a ratio of 1 mg Factor Xa per 25 mg EpoR-Fc and incubated at 6° C. for 18-20 hours.

The digest was then added to Protein A Sepharose 4 Fast Flow [Pharmacia], washed with 100 mM Tris, pH 8, giving a ratio of 0.5 ml packed resin per mg protein. Following a 90 minute incubation with mixing, at 6° C., the resin was separated from the supernatant by centrifugation. SDS/PAGE and Western blots showed that EpoR, free of Fc, was present in the supernatant. The N-terminal sequence for EpoR was correct. The final product was sterile filtered.

EXAMPLE 2 Erythropoietin Binding Assay

The activity of the dimeric fusion protein EpoRFc and the monomeric single-stranded mEpoR protein cleaved from EpoRFc were tested in various biological assays by their ability to neutralize the activity of erythropoietin (Epo).

A. Inhibition of Epo-induced Proliferation of UT7-Epo Cells

An assay for the measurement of Epo activity on the proliferation of UT7Epo cells, which are dependent on Epo for growth [Komatsu et al., Blood, 82:456-464 (1993)] was performed as follows. The Epo used in the experiment is Epogen (2000 U/ml) [Amgen, Thousand Oaks, Calif.], diluted in phosphate buffered saline (PBS) and human serum albumin (HSA) for storage at 4° C. at 200 U/ml. Dilutions of cleaved EpoR or EpoRFc protein samples were made, so that final concentrations ranged from 0.001 to 100 ng/ml.

Samples of either EpoR or EpoRFc were added to wells at 10 ul/well in quadruplicate. Epo (0.2 U/ml) was added to each well. UT7Epo cells (1×10⁵ cells/ml) were plated at 100 ul/well. After the plates were incubated at 37° C. for three days, 10 ul/well of ³ H-thymidine (diluted to 100 mCi/ml in IMDM+10% fetal calf serum (FCS)) were added to a final concentration of 10 uCi/ml. Plates were incubated at 37° C. for four hours with ³ H-thymidine. The 96-well plates were harvested onto glass fiber filters using the Tomtec plate harvester with 10% cold TCA and cold 95% ethanol. Solid scintillant was melted onto the filters and the samples counted. The mean and standard error of quadruplicate samples was determined.

The data were reported as the percent of positive (0.2 U/ml) Epo control and are illustrated in FIG. 1.

B. Inhibition of Epo-induced Proliferation of 32D/Epo wt Cells

Another assay was performed for the measurement of Epo activity on the proliferation of 32D/Epo wt cells (Miura, O. et al., Mol. Cell. Biol., 13:1788-1795 (1993)). 32D/Epo wt is an IL-3 dependent cell line transfected with the human Epo receptor.

This assay is performed as described in Part A above, with the modification that the each well contains 1 U/ml Epo. The results of this assay are illustrated in FIG. 2.

C. Inhibition of Epo-induced CFU-E Colony Formation

A third assay for measuring the ability of Epo to stimulate the differentiation of murine bone marrow cells to hemoglobin producing mature erythrocytes (CFU-E assay) was performed as described below.

Murine bone marrow cells were flushed from the femur of female B2D6F1 mice. The marrow cells (1×10⁵ cells/ml final concentration) were mixed with IMDM, 25% FCS (final) and methylcellulose (0.8% final). 0.4 ml cells was plated per well of 24-well TC plate. EpoRFc (40 ul/well) samples were added and Epo (1 U/ml) was added to each well. Plates were incubated at 37° C., 5% CO2, 6% O₂ for two days.

CFU-E colonies containing 8 or more red cells were counted. The mean and standard error of triplicate samples were determined and data reported as the percent of the positive (1 U/ml) Epo control. The results of this assay are illustrated in FIG. 3.

In all three assays, both the monomeric extracellular domain protein EpoR and the dimeric fusion protein EpoRFc were able to bind, and thereby neutralize, the biological activity of the ligand Epo. However, the dimeric fusion protein EpoRFc was consistently 10 to 100 fold more effective at neutralizing Epo activity than non-fused, monomeric extracellular domain protein EpoR, suggesting that the dimeric antigen had a higher affinity to the natural ligand, Epo. The assay results also confirm that the dimeric fusion protein mimics the cell surface form of the natural EpoR in being able to bind to Epo with greater affinity than the mEpoR domain protein.

EXAMPLE 3 Agonist Antibodies of the Invention

A. Generation of Hybridomas

Mice were immunised s.c. with recombinant EpoRFc (34 ug) in Freund's complete adjuvant and then boosted i.p. 4 weeks later (34 ug) with Freund's incomplete adjuvant. One and three days before fusion mice received 20 ug in PBS i.p. The spleens were harvested and fused with myeloma cells according to the method described in Zola. (Monoclonal Antibodies: A Manual of Techniques, Zola H. ed., Boca Raton, Fla.: CRC Press, 1987).

Positive hybridomas were selected through a primary screen described below. Positives were rescreened using a competitive immunoassay and then BIOcore was used to select hybridomas that expressed high affinity monoclonal antibodies which were then cloned twice by the limiting dilution method.

A1. Primary Screening Assay of Anti EpoRFc Hybridomas

96 well microtitre plates were coated with 100 ul/well of EpoRFc at 0.5 ug/ml in coating buffer (50 mM Na₂ HPO₄, 150 mM NaCl, 0.02% v/v Kathon, pH 7.4) and incubated overnight at 4° C. The well were aspirated and 250 ul/well blocking buffer (1% w/v BSA, 50 mM Tris, 150 mM NaCl, 0.1% v/v Kathon, pH 7.4) added for 1 hour at 37° C. The wells were washed X4 with wash buffer (10 mM Tris, 150 mM NaCl, 0.05% Tween 20, pH 7.4) and 50 ul/well of 40 ug/ml human IgG diluted in assay buffer (0.5% w/v BAS, 0.05% w/v bovine γ globulin, 50 mM Tris, 150 mM NaCl, 7.86 mg/L DTPA, 0.1 g/L Tween-40, 0.02% v/v Kathon, pH 7.4) added followed by 50 ul hybridoma supernatant. The plates were incubated for 1 hour at 37° C. on a plate shaker, the wells washed X4 and then 100 ul/well Europium conjugated anti-mouse IgG added (0.5 ug/ml is assay buffer). After incubation for 1 hour at 37° C. on the plate shaker th wells were again washed X4 and 100 ul/well of enhancement solution added into each well and incubated for 2 min at 22C on the plate shaker and the counts read on a Delfia plate reader.

A2. Isolation of Hybridomas Producing High Affinity Antibodies that Recognise Solution Phase EpoRFc using a Competitive Immunoassay

Microtitre plates were coated with EpoRFc and blocked as above. The wells were washed X4 and then 50 ul of either EpoRec at 6 ug/ml diluted in assay buffer or 50 ul human IgG at 40 ug/ml diluted in assay buffer or 50 ul assay buffer alone were added followed by 50 ul hybridoma supernatant. After incubation for 1 hour at 37° C. on the plate shaker the wells were washed X4 followed by addition of 100 ul/well Europium conjugated anti-mouse IgG at 0.5 ug/ml (diluted in assay buffer). After incubation for 1 hour at 37° C. on the plate shaker the well were again washed X4 and 100 ul/well of enhancement solution added into each well and incubated for 2 min at 22° C. on the plate shaker and the counts read on the Delfia plate reader.

Positive antibodies would be displaced by solution phase EpoRFc and these would thus show a reduction in counts when compared to wells with only assay buffer, antibodies giving a reduction in counts with human IgG would be non specific. High affinity antibodies would show >80% reduction in counts.

A hybridoma designated herein as 1C8 (or alternatively as 5-1C8) has been deposited at the European Collection of Animal Cell Cultures, Porton Down, Salisbury, Wiltshire, SP4 OJG United Kingdom on Jun. 5, 1996 and assigned provisional Accession number 69060519. The deposit referred to herein will be maintained under the terms of the Budapest Treaty on the International Recognition of the Deposit of Micro-organisms for purposes of Patent Procedure. These deposits are provided merely as convenience of those of skill in the art and are not an admission that a deposit is required under 35 U.S.C. §112. The sequence of the polynucleotides contained in the deposited material, as well as the amino acid sequence of the polypeptides encoded thereby, are incorporated herein by reference and are controlling in the event of any conflict with any description of sequences herein. A license may be required to make, use or sell the deposited material, and no such license is hereby granted.

A3. Binding analysis in the BIAcore for the Selection of Antibodies that Bound EpoR with High Affinity

Rabbit anti-mouse Fc (RAMFc) was immobilised to the sensor chip surface (Pharmacia BIosensor protocol) and used as a capture antibody. The run buffer used was 10 mM HEPES, 150 mM NaCl, 3.4 mM EDTA, 0.005% (v/v) Surfactant P 20 at a flow rate of 5 ul/min. 20 ul hybridoma supernatant was injected over the sensor chip surface followed by 20 ul EpoR or EpoRFc (3 ug/ml diluted in run buffer). The surface was regenerated by injection of 15 ul HCL (100 mM) and then 10 ul SDS (0.025%).

High affinity monoclonal antibodies were selected on the basis of a fast on rate and slow off rate with respect to EpoR binding.

B. Assays to Test Agonist Characteristic of Antibodies

The hybridoma supernatants or purified antibodies were then tested for their ability to bind to the naturally occurring EpoR on UT7 or 32D/Epo wt cells in flow cytometry as follows. 5×10⁵ cells per sample of 32D/Epo wt or UT7-Epo cells were resuspended in 50 ul PBS/10%BSA. 5.0 ul of each purified anti-EpoRFc was diluted to 30 ug/ml and incubated on ice for 45 minutes. Cells were washed and resuspended in 50 ul PBS/10% bovine serum albumin (BSA) and 7 ul FITC-labelled goat anti-mouse IgG (Fab')2 [Tago] added for 45 minutes on ice. Cells were again washed in PBS/10%BSA and resuspended in 0.4 ml PBS/10% BSA and then 0.2 ml 3.2% paraformaldehyde added followed by vortexing. Cells were stored at 4° C. until analysis on Becton-Dickinson's FACScan Fluorescence activated cell sorter.

The data, illustrated in FIG. 4, was reported as the % of control antibody fluorescence. As can be seen, four antibodies stained UT7Epo cells while three did not. Interestingly, only one of the four positive antibodies on UT7Epo cells was able to recognize the transfected human Epo receptor in 32D/Epo wt cells, suggesting some differences inthe disposition of the Epo receptor in these cell lines. This also suggests differences in the epitopes recognized by these antibodies.

C. Assays to Test Agonist Activity of Antibodies

(1) Hybridoma supernatants or purified antibodies were tested for their ability to mimic the activity of Epo by stimulating the proliferation of UT7-Epo cells in an assay performed as described in Example 2A above, with the modification that Epo is absent from wells containing the hybridoma supernatants. The only sample ws dilutions of the monoclonal antibodies against EpoRFc dimeric protein. Results of this assay are shown in FIG. 5 for some purified EpoR reactive monoclonal antibodies. Four of the antibodies gave significant proliferative activity, in one case approaching that of Epo itself (1C8). The variability of the extent of peak activity relative to Epo suggests that the way in which the antibodies bind may be an important determinant of activity.

(2) Hybridoma supernatants or purified antibodies were tested for their ability to mimic the activity of Epo by stimulating the proliferation and differentiation of human bone marrow progenitor cells to form red blood cell colonies (CFU-E) similar to the assay described above in FIG. 6. The present assay differed in that the progenitor cells were of human origin.

In this procedure, light density cells from human bone marrow centrifuged over Histopaque 1077 were washed and resuspended at 2.5×10⁶ cells/ml in X-vivo medium (BioWhittaker). The purified monoclonal antibodies were diluted in X-vivo medium, and the Epo positive control was 4 U/ml. For the assay, 0.3 ml cells, 0.3 ml Mab sample (or Epo control) and 0.7 ml X-vivo medium were incubated in a polypropylene tube for 30 min at RT, then 0.9 ml FCS, 0.3 ml 10% BSA and 0.8 ml 3.2% methylcellulose were added. 0.4 ml were plated per well of a 24-well TC dish (Nunc.) This procedure departs from the standard assay in the pre-incubation of cells, X-Vivo and Mab alone for 30 min (without serum, BSA or methylcellulose) prior to plating in methylcellulose.

The results are shown in FIG. 6. Once again, all four antibodies were positive in the UT7Epo proliferation assay were also able to stimulate the generation of mature red blood cells. Again the most potent was antibody 1C8 which gave almost 50% of the maximal activity of human Epo on the same cells. The order of maximal activity was similar to that observed in the proliferative assay.

D. Epitope Mapping of Agonist Antibodies

It was likely that one contributer to the different activities of the agonist antibodies was the epitope recognized on the erythropoietin receptor. To determine if the antibodies recognized overlapping epitopes on the Epo receptor, the ability of antibodies to compete with each other in binding to EpoR or EpoRFc was measured.

RAMFc was immobilised to the sensor chip surface and using a flow rate of 5 ul/min the following sequential injections were used. 5 ul of first monoclonal antibody (25 or 30 ug/ml), 10 ul EpoR (5 ug/ml) or EpoRFc (6 ug/ml), 2×5 ul of nonspecific monoclonal antibodies, (100 ug/ml each of IgG 2bk, IgG 3k, IgG 1k and IgG 2ak), 5 ul of second monoclonal antibody. The surface was generated with 15 ul 0.1M phosphoric acid and 8 ul 0.025% SDS at 10 ul/min. The data are shown in Table I.

Table I Competition of different monoclonal antibodies for epitopes on Epo receptor as measured by BIAcore. Results are expressed as Response Units. The antibody attached to the chip via protein A is shown in the left hand column and each row shows the binding of each monoclonal after prebinding of EpoR or EpoRFc.

    ______________________________________                                                 Measurements are in RU                                                         5-1C8      3-2B6   5-2G6                                               ______________________________________                                         Epo-R                                                                          5-1C8     -25          -21     2                                               3-2B6     -3           -6      269                                             5-2G6     -13          169     --                                              Epo-RFc                                                                        5-1C8     -9.6         6.3     5.2                                             3-2B6     -7           -8      272                                             5-2G6     -11.6        167     -5                                              ______________________________________                                    

The data indicate that of the three agonist antibodies, 2B6 and 2G6 bind to two non-overlapping epitopes since they do not compete for binding to the Epo receptor. In contrast, 1C8 competes with both 2B6 and 2G6, suggesting that it binds to a third distinct epitope which overlaps the other two. Thus there is no single epitope which can lead to agonist activity, but the precise epitope can very likely affect the extent of bioactivity observed. Use of the EpoRFc as antigen seems to generate a wide variety of agonist epitopes.

E. Competition of Antibody Binding with Epo

Another measure of differences between the agonist antibodies is provided by studies which measure the ability of monoclonal antibody to compete with Epo binding to the receptor. These experiments were conducted in two ways. First, a goat anti-human IgG was attached to the BIAcore chip, followed by sequential binding of EpoRFc, Epo and finally monoclonal antibody. In this experiment, pre-binding of Epo blocked the binding of 1C8 by more than 75%, but had only a limited effect on the binding of 1D9, 2G6 and 2B6. Second, if the EpoRFc binding to the chip was followed first by monoclonal antibody and then by Epo, all four monoclonal antibodies could block subsequent binding of Epo. More specifically, a goat anti-human IgG, Fc specific antibody was immobilised on the sensor chip surface. Injection of 25 ul EpoRFc (2 ug/ml) at 5 ul/min was followed by injection of 25 ul Epo (5 ug/ml) then 25 ul Mab (10 ug/ml) at 5 ul/min. RU recorded. The surface was regenerated with injections of 15 ul 0.1M phosphoric acid (5 ul/min) and 8 ul 0.025% SDS at 10 ul/min. and as mentioned above the experiment was repeated reversing the order of addition for EPo and mAB, i.e inject Mab first, then displaced with Epo.

These data, shown in Table II suggest that all four antibodies may block access of Epo to its binding site, but only the 1C8 antibody overlaps substantially with the Epo binding site on the Epo receptor.

Table II Competition of monoclonal antibody binding with Epo binding to Epo receptor as measured by BIAcore. The order to addition is left to right as indicated. The identity of each monoclonal antibody is listed in the left column.

    ______________________________________                                         EpoRFc + Epo + Mab                                                             Mab     EpoR R.U.      Epo R.U. Mab R.U.                                       ______________________________________                                         Buffer  557            118      -9.5                                           1D9     475            106      173                                            2B6     471            106      264                                            2G6     468            104      300                                            1C8     465            104      77                                             ______________________________________                                         EpoR + Mab + Epo                                                               Mab     EpoR R.U.      Mab R.U. Epo R.U.                                       ______________________________________                                         Buffer  462            9.1      105                                            1D9     452            173      101                                            2B6     449            455      9.2                                            2G6     448            474      25                                             1C8     447            436      -196                                           ______________________________________                                    

F. Affinity of the Monoclonal Antibodies to the Epo Receptor

The binding kinetics and affinities of the agonist antibodies was determined by measurements in the BIAcore with both the soluble EpoR and with the dimeric EpoRFc. Specifically, RAMFc was immobilised to the sensor chip surface and a flow rate of 5 ul/min was used with run buffer. The Mab was first bound to the RAMFc (5 ul injection) followed by a 20 ul injection of of EpoR (0-4 ug/ml) or EpoRFc (0-6 ug/ml) then buffer flow for 120 sec and regeneration with 15 ul 0.1M phosphoric acid and 8 ul 0.025% SDS at 10 ul/min. The four antibodies showed quite different kinetics and binding constants as listed in Table III.

Table III Affinities and kinetics of binding of monoclonal antibodies to Epo receptor as measured by BIAcore.

    ______________________________________                                         Mab  Kass. M.sup.-1 s.sup.-1                                                                    Kdiss. (s)                                                                               K.sub.D (M)                                                                            (2nd Dissoc. K.sub.D)                       ______________________________________                                         Binding to Epo-R                                                               1C8  2.54 × 10.sup.5                                                                      5.9 × 10.sup.-3                                                                    2.3 × 10.sup.-8                                                                  4.3 × 10.sup.-9                       2G6  1.64 × 10.sup.5                                                                      4.3 × 10.sup.-4                                                                    2.6 × 10.sup.-9                               2B6   2.4 × 10.sup.5                                                                      1.9 × 10.sup.-4                                                                    .sup. 7.8 × 10.sup.-10                        Binding to Epo-RFc                                                             1C8    4 × 10.sup.5                                                                       N/D        <5 × 10.sup.-10                              2G6  1.77 × 10.sup.5                                                                      N/D        <5 × 10.sup.-10                              2B6  1.96 × 10.sup.5                                                                      N/D        <5 × 10.sup.-10                              ______________________________________                                          N/D No Dissociation                                                      

On the monomeric EpoR, the affinities ranged between 0.75 nM and 23 nM. Interestingly, the most biologically potent antibody, 1C8, had the lowest dissociation constant of 23 nM, and also had a second binding mode with a dissociation constant of 4.3 nM. It was only antibody to show this phenomenon. In contrast, with the dimeric receptor EpoRFc, all four antibodies had non-measurable dissociations, suggesting dissociation constants of less than 500 pM. These data suggest that kinetics may also play a role in the relative agonist activity of different monoclonal antibodies.

All documents cited above are incorporated herein by reference. Numerous modifications and variations of the present invention are included in the above-identified specification and are expected to be obvious to one of skill in the art. Such modifications and alterations to the compositions and processes of the present invention are believed to be encompassed in the scope of the claims appended hereto.

    __________________________________________________________________________     #             SEQUENCE LISTING                                                 - (1) GENERAL INFORMATION:                                                     -    (iii) NUMBER OF SEQUENCES: 13                                             - (2) INFORMATION FOR SEQ ID NO: 1:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 4990 base                                                          (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: double                                                       (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 -     (ix) FEATURE:                                                                      (A) NAME/KEY: CDS                                                              (B) LOCATION: 898..2361                                              #1:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    - TCGCGCGTTT CGGTGATGAC GGTGAAAACC TCTGACACAT GCAGCTCCCG GA - #GACGGTCA          60                                                                           - CAGCTTGTCT GTAAGCGGAT GCCGGGAGCA GACAAGCCCG TCAGGGCGCG TC - #AGCGGGTG         120                                                                           - TTGGCGGGTG TCGGGGCTGG CTTAACTATG CGGCATCAGA GCAGATTGTA CT - #GAGAGTGC         180                                                                           - ACCATATGCG GTGTGAAATA CCGCACAGAT GCGTAAGGAG AAAATACCGC AT - #CAGGCGCC         240                                                                           - ATTCGCCATT CAGGCTGCGC AACTGTTGGG AAGGGCGATC GGTGCGGGCC TC - #TTCGCTAT         300                                                                           - TACGCCAGCT GGCGAAAGGG GGATGTGCTG CAAGGCGATT AAGTTGGGTA AC - #GCCAGGGT         360                                                                           - TTTCCCAGTC ACGACGTTGT AAAACGACGG CCAGTGCCAG TGAATTCGTT GC - #AGGACAGG         420                                                                           - ATGTGGTGCC CGATGTGACT AGCTCTTTGC TGCAGGCCGT CCTATCCTCT GG - #TTCCGATA         480                                                                           - AGAGACCCAG AACTCCGGCC CCCCACCGCC CACCGCCACC CCCATACATA TG - #TGGTACGC         540                                                                           - AAGTAAGAGT GCCTGCGCAT GCCCCATGTG CCCCACCAAG AGTTTTGCAT CC - #CATACAAG         600                                                                           - TCCCCAAAGT GGAGAACCGA ACCAATTCTT CGCGGGCAGA ACAAAAGCTT CT - #GCACACGT         660                                                                           - CTCCACTCGA ATTTGGAGCC GGCCGGCGTG TGCAAAAGAG GTGAATCGAA CG - #AAAGACCC         720                                                                           - GTGTGTAAAG CCGCGTTTCC AAAATGTATA AAACCGAGAG CATCTGGCCA AT - #GTGCATCA         780                                                                           - GTTGTGGTCA GCAGCAAAAT CAAGTGAATC ATCTCAGTGC AACTAAAGGG GG - #GATCCGAT         840                                                                           - ATCCAAGGTT ACCGCGGACT AGTCTAGTAA CGGCCGCCAG TGTGCTGGAA TT - #CGGCT            897                                                                           - ATG GAC CAC CTC GGG GCG TCC CTC TGG CCC CA - #G GTC GGC TCC CTT TGT           945                                                                           Met Asp His Leu Gly Ala Ser Leu Trp Pro Gl - #n Val Gly Ser Leu Cys            #                 15                                                           - CTC CTG CTC GCT GGG GCC GCC TGG GCG CCC CC - #G CCT AAC CTC CCG GAC           993                                                                           Leu Leu Leu Ala Gly Ala Ala Trp Ala Pro Pr - #o Pro Asn Leu Pro Asp            #             30                                                               - CCC AAG TTC GAG AGC AAA GCG GCC TTG CTG GC - #G GCC CGG GGG CCC GAA          1041                                                                           Pro Lys Phe Glu Ser Lys Ala Ala Leu Leu Al - #a Ala Arg Gly Pro Glu            #         45                                                                   - GAG CTT CTG TGC TTC ACC GAG CGG TTG GAG GA - #C TTG GTG TGT TTC TGG          1089                                                                           Glu Leu Leu Cys Phe Thr Glu Arg Leu Glu As - #p Leu Val Cys Phe Trp            #     60                                                                       - GAG GAA GCG GCG AGC GCT GGG GTG GGC CCG GG - #C AAC TAC AGC TTC TCC          1137                                                                           Glu Glu Ala Ala Ser Ala Gly Val Gly Pro Gl - #y Asn Tyr Ser Phe Ser            # 80                                                                           - TAC CAG CTC GAG GAT GAG CCA TGG AAG CTG TG - #T CGC CTG CAC CAG GCT          1185                                                                           Tyr Gln Leu Glu Asp Glu Pro Trp Lys Leu Cy - #s Arg Leu His Gln Ala            #                 95                                                           - CCC ACG GCT CGT GGT GCG GTG CGC TTC TGG TG - #T TCG CTG CCT ACA GCC          1233                                                                           Pro Thr Ala Arg Gly Ala Val Arg Phe Trp Cy - #s Ser Leu Pro Thr Ala            #           110                                                                - GAC ACG TCG AGC TTC GTG CCC CTA GAG TTG CG - #C GTC ACA GCA GCC TCC          1281                                                                           Asp Thr Ser Ser Phe Val Pro Leu Glu Leu Ar - #g Val Thr Ala Ala Ser            #       125                                                                    - GGC GCT CCG CGA TAT CAC CGT GTC ATC CAC AT - #C AAT GAA GTA GTG CTC          1329                                                                           Gly Ala Pro Arg Tyr His Arg Val Ile His Il - #e Asn Glu Val Val Leu            #   140                                                                        - CTA GAC GCC CCC GTG GGG CTG GTG GCG CGG TT - #G GCT GAC GAG AGC GGC          1377                                                                           Leu Asp Ala Pro Val Gly Leu Val Ala Arg Le - #u Ala Asp Glu Ser Gly            145                 1 - #50                 1 - #55                 1 -        #60                                                                            - CAC GTA GTG TTG CGC TGG CTC CCG CCG CCT GA - #G ACA CCC ATG ACG TCT          1425                                                                           His Val Val Leu Arg Trp Leu Pro Pro Pro Gl - #u Thr Pro Met Thr Ser            #               175                                                            - CAC ATC CGC TAC GAG GTG GAC GTC TCG GCC GG - #C AAC GGC GCA GGG AGC          1473                                                                           His Ile Arg Tyr Glu Val Asp Val Ser Ala Gl - #y Asn Gly Ala Gly Ser            #           190                                                                - GTA CAG AGG GTG GAG ATC CTG GAG GGC CGC AC - #C GAG TGT GTG CTG AGC          1521                                                                           Val Gln Arg Val Glu Ile Leu Glu Gly Arg Th - #r Glu Cys Val Leu Ser            #       205                                                                    - AAC CTG CGG GGC CGG ACG CGC TAC ACC TTC GC - #C GTC CGC GCG CGT ATG          1569                                                                           Asn Leu Arg Gly Arg Thr Arg Tyr Thr Phe Al - #a Val Arg Ala Arg Met            #   220                                                                        - GCT GAG CCG AGC TTC GGC GGC TTC TGG AGC GC - #C TGG TCG GAG CCT GTG          1617                                                                           Ala Glu Pro Ser Phe Gly Gly Phe Trp Ser Al - #a Trp Ser Glu Pro Val            225                 2 - #30                 2 - #35                 2 -        #40                                                                            - TCG CTG CTG ACG CCT AGC GAC CTG GAC CCC AT - #T GAG GGC CGT GGT ACC          1665                                                                           Ser Leu Leu Thr Pro Ser Asp Leu Asp Pro Il - #e Glu Gly Arg Gly Thr            #               255                                                            - GAG CCC AAA TCG GCC GAC AAA ACT CAC ACA TG - #C CCA CCG TGC CCA GCA          1713                                                                           Glu Pro Lys Ser Ala Asp Lys Thr His Thr Cy - #s Pro Pro Cys Pro Ala            #           270                                                                - CCT GAA CTC CTG GGG GGA CCG TCA GTC TTC CT - #C TTC CCC CCA AAA CCC          1761                                                                           Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Le - #u Phe Pro Pro Lys Pro            #       285                                                                    - AAG GAC ACC CTC ATG ATC TCC CGG ACC CCT GA - #G GTC ACA TGC GTG GTG          1809                                                                           Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Gl - #u Val Thr Cys Val Val            #   300                                                                        - GTG GAC GTG AGC CAC GAA GAC CCT GAG GTC AA - #G TTC AAC TGG TAC GTG          1857                                                                           Val Asp Val Ser His Glu Asp Pro Glu Val Ly - #s Phe Asn Trp Tyr Val            305                 3 - #10                 3 - #15                 3 -        #20                                                                            - GAC GGC GTG GAG GTG CAT AAT GCC AAG ACA AA - #G CCG CGG GAG GAG CAG          1905                                                                           Asp Gly Val Glu Val His Asn Ala Lys Thr Ly - #s Pro Arg Glu Glu Gln            #               335                                                            - TAC AAC AGC ACG TAC CGG GTG GTC AGC GTC CT - #C ACC GTC CTG CAC CAG          1953                                                                           Tyr Asn Ser Thr Tyr Arg Val Val Ser Val Le - #u Thr Val Leu His Gln            #           350                                                                - GAC TGG CTG AAT GGC AAG GAG TAC AAG TGC AA - #G GTC TCC AAC AAA GCC          2001                                                                           Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Ly - #s Val Ser Asn Lys Ala            #       365                                                                    - CTC CCA GCC CCC ATC GAG AAA ACC ATC TCC AA - #A GCC AAA GGG CAG CCC          2049                                                                           Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Ly - #s Ala Lys Gly Gln Pro            #   380                                                                        - CGA GAA CCA CAG GTG TAC ACC CTG CCC CCA TC - #C CGG GAT GAG CTG ACC          2097                                                                           Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Se - #r Arg Asp Glu Leu Thr            385                 3 - #90                 3 - #95                 4 -        #00                                                                            - AAG AAC CAG GTC AGC CTG ACC TGC CTG GTC AA - #A GGC TTC TAT CCC AGC          2145                                                                           Lys Asn Gln Val Ser Leu Thr Cys Leu Val Ly - #s Gly Phe Tyr Pro Ser            #               415                                                            - GAC ATC GCC GTG GAG TGG GAG AGC AAT GGG CA - #G CCG GAG AAC AAC TAC          2193                                                                           Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gl - #n Pro Glu Asn Asn Tyr            #           430                                                                - AAG ACC ACG CCT CCC GTG CTG GAC TCC GAC GG - #C TCC TTC TTC CTC TAC          2241                                                                           Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gl - #y Ser Phe Phe Leu Tyr            #       445                                                                    - AGC AAG CTC ACC GTG GAC AAG AGC AGG TGG CA - #G CAG GGG AAC GTC TTC          2289                                                                           Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gl - #n Gln Gly Asn Val Phe            #   460                                                                        - TCA TGC TCC GTG ATG CAT GAG GCT CTG CAC AA - #C CAC TAC ACG CAG AAG          2337                                                                           Ser Cys Ser Val Met His Glu Ala Leu His As - #n His Tyr Thr Gln Lys            465                 4 - #70                 4 - #75                 4 -        #80                                                                            - AGC CTC TCC CTG TCT CCG GGT AAA TGAGTGTAGT CT - #AGAAGCTT ACGCGTAGGC         2391                                                                           Ser Leu Ser Leu Ser Pro Gly Lys                                                                485                                                            - CTGAGCTCGC TGATCAGCCT CGAGGATCCA GACATGATAA GATACATTGA TG - #AGTTTGGA        2451                                                                           - CAAACCACAA CTAGAATGCA GTGAAAAAAA TGCTTTATTT GTGAAATTTG TG - #ATGCTATT        2511                                                                           - GCTTTATTTG TAACCATTAT AAGCTGCAAT AAACAAGTTA ACAACAACAA TT - #GCATTCAT        2571                                                                           - TTTATGTTTC AGGTTCAGGG GGAGGTGTGG GAGGTTTTTT AAAGCAAGTA AA - #ACCTCTAC        2631                                                                           - AAATGTGGTA TGGCTGATTA TGATCAGTCG ACCGATGCCC TTGAGAGCCT TC - #AACCCAGT        2691                                                                           - CAGCTCCTTC CGGTGGGCGC GGGGCATGAC TATCGTCGCC GCACTTATGA CT - #GTCTTCTT        2751                                                                           - TATCATGCAA CTCGTAGGAC AGGTGCCGGC AGCGCTCTGG GTCATTTTCG GC - #GAGGACCG        2811                                                                           - CTTTCGCTGG AGCGCGACGA TGATCGGCCT GTCGCTTGCG GTATTCGGAA TC - #TTGCACGC        2871                                                                           - CCTCGCTCAA GCCTTCGTCA CTGGTCCCGC CACCAAACGT TTCGGCGAGA AG - #CAGGCCAT        2931                                                                           - TATCGCCGGC ATGGCGGCCG ACGCGCTGGG CTACGTCTTG CTGGCGTTCG CG - #ACGCGAGG        2991                                                                           - CTGGATGGCC TTCCCCATTA TGATTCTTCT CGCTTCCGGC GGCATCGGGA TG - #CCCGCGTT        3051                                                                           - GCAGGCCATG CTGTCCAGGC AGGTAGATGA CGACCATCAG GGACAGCTTC AA - #GGATCGCT        3111                                                                           - CGCGGCTCTT ACCAGCCAGC AAAAGGCCAG GAACCGTAAA AAGGCCGCGT TG - #CTGGCGTT        3171                                                                           - TTTCCATAGG CTCCGCCCCC CTGACGAGCA TCACAAAAAT CGACGCTCAA GT - #CAGAGGTG        3231                                                                           - GCGAAACCCG ACAGGACTAT AAAGATACCA GGCGTTTCCC CCTGGAAGCT CC - #CTCGTGCG        3291                                                                           - CTCTCCTGTT CCGACCCTGC CGCTTACCGG ATACCTGTCC GCCTTTCTCC CT - #TCGGGAAG        3351                                                                           - CGTGGCGCTT TCTCAATGCT CACGCTGTAG GTATCTCAGT TCGGTGTAGG TC - #GTTCGCTC        3411                                                                           - CAAGCTGGGC TGTGTGCACG AACCCCCCGT TCAGCCCGAC CGCTGCGCCT TA - #TCCGGTAA        3471                                                                           - CTATCGTCTT GAGTCCAACC CGGTAAGACA CGACTTATCG CCACTGGCAG CA - #GCCACTGG        3531                                                                           - TAACAGGATT AGCAGAGCGA GGTATGTAGG CGGTGCTACA GAGTTCTTGA AG - #TGGTGGCC        3591                                                                           - TAACTACGGC TACACTAGAA GGACAGTATT TGGTATCTGC GCTCTGCTGA AG - #CCAGTTAC        3651                                                                           - CTTCGGAAAA AGAGTTGGTA GCTCTTGATC CGGCAAACAA ACCACCGCTG GT - #AGCGGTGG        3711                                                                           - TTTTTTTGTT TGCAAGCAGC AGATTACGCG CAGAAAAAAA GGATCTCAAG AA - #GATCCTTT        3771                                                                           - GATCTTTTCT ACGGGGTCTG ACGCTCAGTG GAACGAAAAC TCACGTTAAG GG - #ATTTTGGT        3831                                                                           - CATGAGATTA TCAAAAAGGA TCTTCACCTA GATCCTTTTA AATTAAAAAT GA - #AGTTTTAA        3891                                                                           - ATCAATCTAA AGTATATATG AGTAAACTTG GTCTGACAGT TACCAATGCT TA - #ATCAGTGA        3951                                                                           - GGCACCTATC TCAGCGATCT GTCTATTTCG TTCATCCATA GTTGCCTGAC TC - #CCCGTCGT        4011                                                                           - GTAGATAACT ACGATACGGG AGGGCTTACC ATCTGGCCCC AGTGCTGCAA TG - #ATACCGCG        4071                                                                           - AGACCCACGC TCACCGGCTC CAGATTTATC AGCAATAAAC CAGCCAGCCG GA - #AGGGCCGA        4131                                                                           - GCGCAGAAGT GGTCCTGCAA CTTTATCCGC CTCCATCCAG TCTATTAATT GT - #TGCCGGGA        4191                                                                           - AGCTAGAGTA AGTAGTTCGC CAGTTAATAG TTTGCGCAAC GTTGTTGCCA TT - #GCTGCAGG        4251                                                                           - CATCGTGGTG TCACGCTCGT CGTTTGGTAT GGCTTCATTC AGCTCCGGTT CC - #CAACGATC        4311                                                                           - AAGGCGAGTT ACATGATCCC CCATGTTGTG CAAAAAAGCG GTTAGCTCCT TC - #GGTCCTCC        4371                                                                           - GATCGTTGTC AGAAGTAAGT TGGCCGCAGT GTTATCACTC ATGGTTATGG CA - #GCACTGCA        4431                                                                           - TAATTCTCTT ACTGTCATGC CATCCGTAAG ATGCTTTTCT GTGACTGGTG AG - #TACTCAAC        4491                                                                           - CAAGTCATTC TGAGAATAGT GTATGCGGCG ACCGAGTTGC TCTTGCCCGG CG - #TCAACACG        4551                                                                           - GGATAATACC GCGCCACATA GCAGAACTTT AAAAGTGCTC ATCATTGGAA AA - #CGTTCTTC        4611                                                                           - GGGGCGAAAA CTCTCAAGGA TCTTACCGCT GTTGAGATCC AGTTCGATGT AA - #CCCACTCG        4671                                                                           - TGCACCCAAC TGATCTTCAG CATCTTTTAC TTTCACCAGC GTTTCTGGGT GA - #GCAAAAAC        4731                                                                           - AGGAAGGCAA AATGCCGCAA AAAAGGGAAT AAGGGCGACA CGGAAATGTT GA - #ATACTCAT        4791                                                                           - ACTCTTCCTT TTTCAATATT ATTGAAGCAT TTATCAGGGT TATTGTCTCA TG - #AGCGGATA        4851                                                                           - CATATTTGAA TGTATTTAGA AAAATAAACA AATAGGGGTT CCGCGCACAT TT - #CCCCGAAA        4911                                                                           - AGTGCCACCT GACGTCTAAG AAACCATTAT TATCATGACA TTAACCTATA AA - #AATAGGCG        4971                                                                           #                 499 - #0                                                     - (2) INFORMATION FOR SEQ ID NO: 2:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 488 amino                                                          (B) TYPE: amino acid                                                           (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: protein                                              #2:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    - Met Asp His Leu Gly Ala Ser Leu Trp Pro Gl - #n Val Gly Ser Leu Cys          #                 15                                                           - Leu Leu Leu Ala Gly Ala Ala Trp Ala Pro Pr - #o Pro Asn Leu Pro Asp          #             30                                                               - Pro Lys Phe Glu Ser Lys Ala Ala Leu Leu Al - #a Ala Arg Gly Pro Glu          #         45                                                                   - Glu Leu Leu Cys Phe Thr Glu Arg Leu Glu As - #p Leu Val Cys Phe Trp          #     60                                                                       - Glu Glu Ala Ala Ser Ala Gly Val Gly Pro Gl - #y Asn Tyr Ser Phe Ser          # 80                                                                           - Tyr Gln Leu Glu Asp Glu Pro Trp Lys Leu Cy - #s Arg Leu His Gln Ala          #                 95                                                           - Pro Thr Ala Arg Gly Ala Val Arg Phe Trp Cy - #s Ser Leu Pro Thr Ala          #           110                                                                - Asp Thr Ser Ser Phe Val Pro Leu Glu Leu Ar - #g Val Thr Ala Ala Ser          #       125                                                                    - Gly Ala Pro Arg Tyr His Arg Val Ile His Il - #e Asn Glu Val Val Leu          #   140                                                                        - Leu Asp Ala Pro Val Gly Leu Val Ala Arg Le - #u Ala Asp Glu Ser Gly          145                 1 - #50                 1 - #55                 1 -        #60                                                                            - His Val Val Leu Arg Trp Leu Pro Pro Pro Gl - #u Thr Pro Met Thr Ser          #               175                                                            - His Ile Arg Tyr Glu Val Asp Val Ser Ala Gl - #y Asn Gly Ala Gly Ser          #           190                                                                - Val Gln Arg Val Glu Ile Leu Glu Gly Arg Th - #r Glu Cys Val Leu Ser          #       205                                                                    - Asn Leu Arg Gly Arg Thr Arg Tyr Thr Phe Al - #a Val Arg Ala Arg Met          #   220                                                                        - Ala Glu Pro Ser Phe Gly Gly Phe Trp Ser Al - #a Trp Ser Glu Pro Val          225                 2 - #30                 2 - #35                 2 -        #40                                                                            - Ser Leu Leu Thr Pro Ser Asp Leu Asp Pro Il - #e Glu Gly Arg Gly Thr          #               255                                                            - Glu Pro Lys Ser Ala Asp Lys Thr His Thr Cy - #s Pro Pro Cys Pro Ala          #           270                                                                - Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Le - #u Phe Pro Pro Lys Pro          #       285                                                                    - Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Gl - #u Val Thr Cys Val Val          #   300                                                                        - Val Asp Val Ser His Glu Asp Pro Glu Val Ly - #s Phe Asn Trp Tyr Val          305                 3 - #10                 3 - #15                 3 -        #20                                                                            - Asp Gly Val Glu Val His Asn Ala Lys Thr Ly - #s Pro Arg Glu Glu Gln          #               335                                                            - Tyr Asn Ser Thr Tyr Arg Val Val Ser Val Le - #u Thr Val Leu His Gln          #           350                                                                - Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Ly - #s Val Ser Asn Lys Ala          #       365                                                                    - Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Ly - #s Ala Lys Gly Gln Pro          #   380                                                                        - Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Se - #r Arg Asp Glu Leu Thr          385                 3 - #90                 3 - #95                 4 -        #00                                                                            - Lys Asn Gln Val Ser Leu Thr Cys Leu Val Ly - #s Gly Phe Tyr Pro Ser          #               415                                                            - Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gl - #n Pro Glu Asn Asn Tyr          #           430                                                                - Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gl - #y Ser Phe Phe Leu Tyr          #       445                                                                    - Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gl - #n Gln Gly Asn Val Phe          #   460                                                                        - Ser Cys Ser Val Met His Glu Ala Leu His As - #n His Tyr Thr Gln Lys          465                 4 - #70                 4 - #75                 4 -        #80                                                                            - Ser Leu Ser Leu Ser Pro Gly Lys                                                              485                                                            - (2) INFORMATION FOR SEQ ID NO: 3:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 6367 base                                                          (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: double                                                       (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #3:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    - GACGTCGACG GATCGGGAGA TCGGGGATCG ATCCGTCGAC GTACGACTAG TT - #ATTAATAG          60                                                                           - TAATCAATTA CGGGGTCATT AGTTCATAGC CCATATATGG AGTTCCGCGT TA - #CATAACTT         120                                                                           - ACGGTAAATG GCCCGCCTGG CTGACCGCCC AACGACCCCC GCCCATTGAC GT - #CAATAATG         180                                                                           - ACGTATGTTC CCATAGTAAC GCCAATAGGG ACTTTCCATT GACGTCAATG GG - #TGGACTAT         240                                                                           - TTACGGTAAA CTGCCCACTT GGCAGTACAT CAAGTGTATC ATATGCCAAG TA - #CGCCCCCT         300                                                                           - ATTGACGTCA ATGACGGTAA ATGGCCCGCC TGGCATTATG CCCAGTACAT GA - #CCTTATGG         360                                                                           - GACTTTCCTA CTTGGCAGTA CATCTACGTA TTAGTCATCG CTATTACCAT GG - #TGATGCGG         420                                                                           - TTTTGGCAGT ACATCAATGG GCGTGGATAG CGGTTTGACT CACGGGGATT TC - #CAAGTCTC         480                                                                           - CACCCCATTG ACGTCAATGG GAGTTTGTTT TGGCACCAAA ATCAACGGGA CT - #TTCCAAAA         540                                                                           - TGTCGTAACA ACTCCGCCCC ATTGACGCAA ATGGGCGGTA GGCGTGTACG GT - #GGGAGGTC         600                                                                           - TATATAAGCA GAGCTGGGTA CGTGAACCGT CAGATCGCCT GGAGACGCCA TC - #GAATTCGG         660                                                                           - TTACCTGCAG ATATCAAGCT AATTCGGTAC CGAGCCCAAA TCGGCCGACA AA - #ACTCACAC         720                                                                           - ATGCCCACCG TGCCCAGCAC CTGAACTCCT GGGGGGACCG TCAGTCTTCC TC - #TTCCCCCC         780                                                                           - AAAACCCAAG GACACCCTCA TGATCTCCCG GACCCCTGAG GTCACATGCG TG - #GTGGTGGA         840                                                                           - CGTGAGCCAC GAAGACCCTG AGGTCAAGTT CAACTGGTAC GTGGACGGCG TG - #GAGGTGCA         900                                                                           - TAATGCCAAG ACAAAGCCGC GGGAGGAGCA GTACAACAGC ACGTACCGGG TG - #GTCAGCGT         960                                                                           - CCTCACCGTC CTGCACCAGG ACTGGCTGAA TGGCAAGGAG TACAAGTGCA AG - #GTCTCCAA        1020                                                                           - CAAAGCCCTC CCAGCCCCCA TCGAGAAAAC CATCTCCAAA GCCAAAGGGC AG - #CCCCGAGA        1080                                                                           - ACCACAGGTG TACACCCTGC CCCCATCCCG GGATGAGCTG ACCAAGAACC AG - #GTCAGCCT        1140                                                                           - GACCTGCCTG GTCAAAGGCT TCTATCCCAG CGACATCGCC GTGGAGTGGG AG - #AGCAATGG        1200                                                                           - GCAGCCGGAG AACAACTACA AGACCACGCC TCCCGTGCTG GACTCCGACG GC - #TCCTTCTT        1260                                                                           - CCTCTACAGC AAGCTCACCG TGGACAAGAG CAGGTGGCAG CAGGGGAACG TC - #TTCTCATG        1320                                                                           - CTCCGTGATG CATGAGGCTC TGCACAACCA CTACACGCAG AAGAGCCTCT CC - #CTGTCTCC        1380                                                                           - GGGTAAATGA GTGTAGTCTA GAGCTCGCTG ATCAGCCTCG ACTGTGCCTT CT - #AGTTGCCA        1440                                                                           - GCCATCTGTT GTTTGCCCCT CCCCCGTGCC TTCCTTGACC CTGGAAGGTG CC - #ACTCCCAC        1500                                                                           - TGTCCTTTCC TAATAAAATG AGGAAATTGC ATCGCATTGT CTGAGTAGGT GT - #CATTCTAT        1560                                                                           - TCTGGGGGGT GGGGTGGGGC AGGACAGCAA GGGGGAGGAT TGGGAAGACA AT - #AGCAGGCA        1620                                                                           - TGCTGGGGAT GCGGTGGGCT CTATGGAACC AGCTGGGGCT CGAGGGGGGA TC - #TCCCGATC        1680                                                                           - CCCAGCTTTG CTTCTCAATT TCTTATTTGC ATAATGAGAA AAAAAGGAAA AT - #TAATTTTA        1740                                                                           - ACACCAATTC AGTAGTTGAT TGAGCAAATG CGTTGCCAAA AAGGATGCTT TA - #GAGACAGT        1800                                                                           - GTTCTCTGCA CAGATAAGGA CAAACATTAT TCAGAGGGAG TACCCAGAGC TG - #AGACTCCT        1860                                                                           - AAGCCAGTGA GTGGCACAGC ATTCTAGGGA GAAATATGCT TGTCATCACC GA - #AGCCTGAT        1920                                                                           - TCCGTAGAGC CACACCTTGG TAAGGGCCAA TCTGCTCACA CAGGATAGAG AG - #GGCAGGAG        1980                                                                           - CCAGGGCAGA GCATATAAGG TGAGGTAGGA TCAGTTGCTC CTCACATTTG CT - #TCTGACAT        2040                                                                           - AGTTGTGTTG GGAGCTTGGA TAGCTTGGAC AGCTCAGGGC TGCGATTTCG CG - #CCAAACTT        2100                                                                           - GACGGCAATC CTAGCGTGAA GGCTGGTAGG ATTTTATCCC CGCTGCCATC AT - #GGTTCGAC        2160                                                                           - CATTGAACTG CATCGTCGCC GTGTCCCAAA ATATGGGGAT TGGCAAGAAC GG - #AGACCTAC        2220                                                                           - CCTGGCCTCC GCTCAGGAAC GAGTTCAAGT ACTTCCAAAG AATGACCACA AC - #CTCTTCAG        2280                                                                           - TGGAAGGTAA ACAGAATCTG GTGATTATGG GTAGGAAAAC CTGGTTCTCC AT - #TCCTGAGA        2340                                                                           - AGAATCGACC TTTAAAGGAC AGAATTAATA TAGTTCTCAG TAGAGAACTC AA - #AGAACCAC        2400                                                                           - CACGAGGAGC TCATTTTCTT GCCAAAAGTT TGGATGATGC CTTAAGACTT AT - #TGAACAAC        2460                                                                           - CGGAATTGGC AAGTAAAGTA GACATGGTTT GGATAGTCGG AGGCAGTTCT GT - #TTACCAGG        2520                                                                           - AAGCCATGAA TCAACCAGGC CACCTTAGAC TCTTTGTGAC AAGGATCATG CA - #GGAATTTG        2580                                                                           - AAAGTGACAC GTTTTTCCCA GAAATTGATT TGGGGAAATA TAAACTTCTC CC - #AGAATACC        2640                                                                           - CAGGCGTCCT CTCTGAGGTC CAGGAGGAAA AAGGCATCAA GTATAAGTTT GA - #AGTCTACG        2700                                                                           - AGAAGAAAGA CTAACAGGAA GATGCTTTCA AGTTCTCTGC TCCCCTCCTA AA - #GCTATGCA        2760                                                                           - TTTTTATAAG ACCATGCTAG CTTGAACTTG TTTATTGCAG CTTATAATGG TT - #ACAAATAA        2820                                                                           - AGCAATAGCA TCACAAATTT CACAAATAAA GCATTTTTTT CACTGCATTC TA - #GTTGTGGT        2880                                                                           - TTGTCCAAAC TCATCAATGT ATCTTATCAT GTCTGGATCA ACGATAGCTT AT - #CTGTGGGC        2940                                                                           - GATGCCAAGC ACCTGGATGC TGTTGGTTTC CTGCTACTGA TTTAGAAGCC AT - #TTGCCCCC        3000                                                                           - TGAGTGGGGC TTGGGAGCAC TAACTTTCTC TTTCAAAGGA AGCAATGCAG AA - #AGAAAAGC        3060                                                                           - ATACAAAGTA TAAGCTGCCA TGTAATAATG GAAGAAGATA AGGTTGTATG AA - #TTAGATTT        3120                                                                           - ACATACTTCT GAATTGAAAC TAAACACCTT TAAATTCTTA AATATATAAC AC - #ATTTCATA        3180                                                                           - TGAAAGTATT TTACATAAGT AACTCAGATA CATAGAAAAC AAAGCTAATG AT - #AGGTGTCC        3240                                                                           - CTAAAAGTTC ATTTATTAAT TCTACAAATG ATGAGCTGGC CATCAAAATT CC - #AGCTCAAT        3300                                                                           - TCTTCAACGA ATTAGAAAGA GCAATCTGCA AACTCATCTG GAATAACAAA AA - #ACCTAGGA        3360                                                                           - TAGCAAAAAC TCTTCTCAAG GATAAAAGAA CCTCTGGTGG AATCACCATG CC - #TGACCTAA        3420                                                                           - AGCTGTACTA CAGAGCAATT GTGATAAAAA CTGCATGGTA CTGATATAGA AA - #CGGACAAG        3480                                                                           - TAGACCAATG GAATAGAACC CACACACCTA TGGTCACTTG ATCTTCAACA AG - #AGAGCTAA        3540                                                                           - AACCATCCAC TGGAAAAAAG ACAGCATTTT CAACAAATGG TGCTGGCACA AC - #TGGTGGTT        3600                                                                           - ATCATGGAGA AGAATGTGAA TTGATCCATT CCAATCTCCT TGTACTAAGG TC - #AAATCTAA        3660                                                                           - GTGGATCAAG GAACTCCACA TAAAACCAGA GACACTGAAA CTTATAGAGG AG - #AAAGTGGG        3720                                                                           - GAAAAGCCTC GAAGATATGG GCACAGGGGA AAAATTCCTG AATAGAACAG CA - #ATGGCTTG        3780                                                                           - TGCTGTAAGA TCGAGAATTG ACAAATGGGA CCTCATGAAA CTCCAAAGCT AT - #CGGATCAA        3840                                                                           - TTCCTCCAAA AAAGCCTCCT CACTACTTCT GGAATAGCTC AGAGGCCGAG GC - #GGCCTCGG        3900                                                                           - CCTCTGCATA AATAAAAAAA ATTAGTCAGC CATGCATGGG GCGGAGAATG GG - #CGGAACTG        3960                                                                           - GGCGGAGTTA GGGGCGGGAT GGGCGGAGTT AGGGGCGGGA CTATGGTTGC TG - #ACTAATTG        4020                                                                           - AGATGCATGC TTTGCATACT TCTGCCTGCT GGGGAGCCTG GGGACTTTCC AC - #ACCTGGTT        4080                                                                           - GCTGACTAAT TGAGATGCAT GCTTTGCATA CTTCTGCCTG CTGGGGAGCC TG - #GGGACTTT        4140                                                                           - CCACACCCTA ACTGACACAC ATTCCACAGA ATTAATTCCC GATCCCGTCG AC - #CTCGAGAG        4200                                                                           - CTTGGCGTAA TCATGGTCAT AGCTGTTTCC TGTGTGAAAT TGTTATCCGC TC - #ACAATTCC        4260                                                                           - ACACAACATA CGAGCCGGAA GCATAAAGTG TAAAGCCTGG GGTGCCTAAT GA - #GTGAGCTA        4320                                                                           - ACTCACATTA ATTGCGTTGC GCTCACTGCC CGCTTTCCAG TCGGGAAACC TG - #TCGTGCCA        4380                                                                           - GCTGCATTAA TGAATCGGCC AACGCGCGGG GAGAGGCGGT TTGCGTATTG GG - #CGCTCTTC        4440                                                                           - CGCTTCCTCG CTCACTGACT CGCTGCGCTC GGTCGTTCGG CTGCGGCGAG CG - #GTATCAGC        4500                                                                           - TCACTCAAAG GCGGTAATAC GGTTATCCAC AGAATCAGGG GATAACGCAG GA - #AAGAACAT        4560                                                                           - GTGAGCAAAA GGCCAGCAAA AGGCCAGGAA CCGTAAAAAG GCCGCGTTGC TG - #GCGTTTTT        4620                                                                           - CCATAGGCTC CGCCCCCCTG ACGAGCATCA CAAAAATCGA CGCTCAAGTC AG - #AGGTGGCG        4680                                                                           - AAACCCGACA GGACTATAAA GATACCAGGC GTTTCCCCCT GGAAGCTCCC TC - #GTGCGCTC        4740                                                                           - TCCTGTTCCG ACCCTGCCGC TTACCGGATA CCTGTCCGCC TTTCTCCCTT CG - #GGAAGCGT        4800                                                                           - GGCGCTTTCT CAATGCTCAC GCTGTAGGTA TCTCAGTTCG GTGTAGGTCG TT - #CGCTCCAA        4860                                                                           - GCTGGGCTGT GTGCACGAAC CCCCCGTTCA GCCCGACCGC TGCGCCTTAT CC - #GGTAACTA        4920                                                                           - TCGTCTTGAG TCCAACCCGG TAAGACACGA CTTATCGCCA CTGGCAGCAG CC - #ACTGGTAA        4980                                                                           - CAGGATTAGC AGAGCGAGGT ATGTAGGCGG TGCTACAGAG TTCTTGAAGT GG - #TGGCCTAA        5040                                                                           - CTACGGCTAC ACTAGAAGGA CAGTATTTGG TATCTGCGCT CTGCTGAAGC CA - #GTTACCTT        5100                                                                           - CGGAAAAAGA GTTGGTAGCT CTTGATCCGG CAAACAAACC ACCGCTGGTA GC - #GGTGGTTT        5160                                                                           - TTTTGTTTGC AAGCAGCAGA TTACGCGCAG AAAAAAAGGA TCTCAAGAAG AT - #CCTTTGAT        5220                                                                           - CTTTTCTACG GGGTCTGACG CTCAGTGGAA CGAAAACTCA CGTTAAGGGA TT - #TTGGTCAT        5280                                                                           - GAGATTATCA AAAAGGATCT TCACCTAGAT CCTTTTAAAT TAAAAATGAA GT - #TTTAAATC        5340                                                                           - AATCTAAAGT ATATATGAGT AAACTTGGTC TGACAGTTAC CAATGCTTAA TC - #AGTGAGGC        5400                                                                           - ACCTATCTCA GCGATCTGTC TATTTCGTTC ATCCATAGTT GCCTGACTCC CC - #GTCGTGTA        5460                                                                           - GATAACTACG ATACGGGAGG GCTTACCATC TGGCCCCAGT GCTGCAATGA TA - #CCGCGAGA        5520                                                                           - CCCACGCTCA CCGGCTCCAG ATTTATCAGC AATAAACCAG CCAGCCGGAA GG - #GCCGAGCG        5580                                                                           - CAGAAGTGGT CCTGCAACTT TATCCGCCTC CATCCAGTCT ATTAATTGTT GC - #CGGGAAGC        5640                                                                           - TAGAGTAAGT AGTTCGCCAG TTAATAGTTT GCGCAACGTT GTTGCCATTG CT - #ACAGGCAT        5700                                                                           - CGTGGTGTCA CGCTCGTCGT TTGGTATGGC TTCATTCAGC TCCGGTTCCC AA - #CGATCAAG        5760                                                                           - GCGAGTTACA TGATCCCCCA TGTTGTGCAA AAAAGCGGTT AGCTCCTTCG GT - #CCTCCGAT        5820                                                                           - CGTTGTCAGA AGTAAGTTGG CCGCAGTGTT ATCACTCATG GTTATGGCAG CA - #CTGCATAA        5880                                                                           - TTCTCTTACT GTCATGCCAT CCGTAAGATG CTTTTCTGTG ACTGGTGAGT AC - #TCAACCAA        5940                                                                           - GTCATTCTGA GAATAGTGTA TGCGGCGACC GAGTTGCTCT TGCCCGGCGT CA - #ATACGGGA        6000                                                                           - TAATACCGCG CCACATAGCA GAACTTTAAA AGTGCTCATC ATTGGAAAAC GT - #TCTTCGGG        6060                                                                           - GCGAAAACTC TCAAGGATCT TACCGCTGTT GAGATCCAGT TCGATGTAAC CC - #ACTCGTGC        6120                                                                           - ACCCAACTGA TCTTCAGCAT CTTTTACTTT CACCAGCGTT TCTGGGTGAG CA - #AAAACAGG        6180                                                                           - AAGGCAAAAT GCCGCAAAAA AGGGAATAAG GGCGACACGG AAATGTTGAA TA - #CTCATACT        6240                                                                           - CTTCCTTTTT CAATATTATT GAAGCATTTA TCAGGGTTAT TGTCTCATGA GC - #GGATACAT        6300                                                                           - ATTTGAATGT ATTTAGAAAA ATAAACAAAT AGGGGTTCCG CGCACATTTC CC - #CGAAAAGT        6360                                                                           #        6367                                                                  - (2) INFORMATION FOR SEQ ID NO: 4:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 38 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #4:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #     38           CGGG GCGTCCCTCT GGCCCCAG                                    - (2) INFORMATION FOR SEQ ID NO: 5:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 33 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #5:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #         33       CGTC CCTCTGGCCC CAG                                         - (2) INFORMATION FOR SEQ ID NO: 6:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 38 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #6:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #     38           CCAC ATAGCTGGGG GGCAGAGG                                    - (2) INFORMATION FOR SEQ ID NO: 7:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 33 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #7:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #         33       TAGC TGGGGGGCAG AGG                                         - (2) INFORMATION FOR SEQ ID NO: 8:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 41 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #8:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #   41             GGTC GCTAGGCGTC AGCAGCGACA C                                - (2) INFORMATION FOR SEQ ID NO: 9:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 36 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #9:   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #       36         CTAG GCGTCAGCAG CGACAC                                      - (2) INFORMATION FOR SEQ ID NO: 10:                                           -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 43 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #10:  (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    # 43               GCCC AAATCGGCCG ACAAAACTCA CAC                              - (2) INFORMATION FOR SEQ ID NO: 11:                                           -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 28 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #11:  (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #             28   GGCT TTGTCTTG                                               - (2) INFORMATION FOR SEQ ID NO: 12:                                           -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 27 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #12:  (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #             27   GATA TCAAGCT                                                - (2) INFORMATION FOR SEQ ID NO: 13:                                           -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 27 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: unknown                                                      (D) TOPOLOGY: Not Relev - #ant                                       -     (ii) MOLECULE TYPE: cDNA                                                 #13:  (xi) SEQUENCE DESCRIPTION: SEQ ID NO:                                    #             27   GCAG GTAACCG                                                __________________________________________________________________________ 

What is claimed is:
 1. A monoclonal antibody produced by the hybridoma ECACC
 96060519. 2. A hybridoma ECACC
 96060519. 